diff --git a/frontend/components/Calculator.vue b/frontend/components/Calculator.vue
new file mode 100644
index 0000000..3a91aa6
--- /dev/null
+++ b/frontend/components/Calculator.vue
@@ -0,0 +1,235 @@
+<template>
+  <div
+      ref="el"
+      :style="style"
+      class="fixed z-[999] w-72 bg-white dark:bg-gray-900 shadow-2xl rounded-xl border border-gray-200 dark:border-gray-800 p-4 select-none touch-none"
+  >
+    <div class="flex items-center justify-between mb-4 cursor-move border-b pb-2 dark:border-gray-800">
+      <div class="flex items-center gap-2 text-gray-500">
+        <UIcon name="i-heroicons-calculator" />
+        <span class="text-xs font-bold uppercase tracking-wider">Kalkulator</span>
+      </div>
+      <div class="flex items-center gap-1">
+        <UTooltip text="Verlauf">
+          <UButton
+              color="gray"
+              variant="ghost"
+              :icon="showHistory ? 'i-heroicons-clock-solid' : 'i-heroicons-clock'"
+              size="xs"
+              @click="showHistory = !showHistory"
+          />
+        </UTooltip>
+        <UTooltip text="Schließen (Esc)">
+          <UButton
+              color="gray"
+              variant="ghost"
+              icon="i-heroicons-x-mark"
+              size="xs"
+              @click="store.isOpen = false"
+          />
+        </UTooltip>
+      </div>
+    </div>
+
+    <div v-if="!showHistory">
+      <div
+          class="bg-gray-100 dark:bg-gray-800 p-3 rounded-lg mb-4 text-right border border-gray-200 dark:border-gray-700 cursor-pointer group relative"
+          @click="copyDisplay"
+      >
+        <div class="text-[10px] text-gray-500 h-4 font-mono uppercase tracking-tighter">
+          Speicher: {{ Number(store.memory).toFixed(2).replace('.', ',') }} €
+        </div>
+        <div class="text-2xl font-mono truncate tracking-tighter">{{ store.display }}</div>
+
+        <div class="absolute inset-0 flex items-center justify-center bg-primary-500/10 opacity-0 group-hover:opacity-100 transition-opacity rounded-lg">
+          <span class="text-[10px] font-bold text-primary-600 uppercase">
+            {{ copied ? 'Kopiert!' : 'Klicken zum Kopieren' }}
+          </span>
+        </div>
+      </div>
+
+      <div class="grid grid-cols-4 gap-2">
+        <UTooltip text="Brutto (+19%)"><UButton color="green" variant="soft" block size="xs" @click="applyTax(19)">+19%</UButton></UTooltip>
+        <UTooltip text="Brutto (+7%)"><UButton color="green" variant="soft" block size="xs" @click="applyTax(7)">+7%</UButton></UTooltip>
+        <UTooltip text="Netto (-19%)"><UButton color="rose" variant="soft" block size="xs" @click="removeTax(19)">-19%</UButton></UTooltip>
+        <UTooltip text="Netto (-7%)"><UButton color="rose" variant="soft" block size="xs" @click="removeTax(7)">-7%</UButton></UTooltip>
+
+        <UTooltip text="Löschen"><UButton color="gray" variant="ghost" block @click="clear">C</UButton></UTooltip>
+        <UTooltip text="Speicher +"><UButton color="gray" variant="ghost" block @click="addToSum">M+</UButton></UTooltip>
+        <UTooltip text="Speicher Reset"><UButton color="gray" variant="ghost" block @click="store.memory = 0">MC</UButton></UTooltip>
+        <UButton color="primary" variant="soft" @click="setOperator('/')">/</UButton>
+
+        <UButton v-for="n in [7, 8, 9]" :key="n" color="white" @click="appendNumber(n)">{{ n }}</UButton>
+        <UButton color="primary" variant="soft" @click="setOperator('*')">×</UButton>
+
+        <UButton v-for="n in [4, 5, 6]" :key="n" color="white" @click="appendNumber(n)">{{ n }}</UButton>
+        <UButton color="primary" variant="soft" @click="setOperator('-')">-</UButton>
+
+        <UButton v-for="n in [1, 2, 3]" :key="n" color="white" @click="appendNumber(n)">{{ n }}</UButton>
+        <UButton color="primary" variant="soft" @click="setOperator('+')">+</UButton>
+
+        <UButton color="white" class="col-span-2" @click="appendNumber(0)">0</UButton>
+        <UButton color="white" @click="addComma">,</UButton>
+        <UButton color="primary" block @click="calculate">=</UButton>
+      </div>
+    </div>
+
+    <div v-else class="h-[270px] flex flex-col animate-in fade-in duration-200">
+      <div class="flex-1 overflow-y-auto space-y-2 pr-1 custom-scrollbar">
+        <div v-if="store.history.length === 0" class="text-center text-gray-400 text-xs mt-10 italic">
+          Keine Berechnungen im Verlauf
+        </div>
+        <div
+            v-for="(item, i) in store.history" :key="i"
+            class="p-2 bg-gray-50 dark:bg-gray-800 rounded text-right border-l-2 border-primary-500 cursor-pointer hover:bg-primary-50 dark:hover:bg-primary-900/20 transition-colors"
+            @click="useHistoryItem(item.result)"
+        >
+          <div class="text-[10px] text-gray-400">{{ item.expression }} =</div>
+          <div class="text-sm font-bold">{{ item.result }}</div>
+        </div>
+      </div>
+      <UButton
+          color="gray"
+          variant="ghost"
+          size="xs"
+          block
+          class="mt-2"
+          icon="i-heroicons-trash"
+          @click="store.history = []"
+      >
+        Verlauf leeren
+      </UButton>
+    </div>
+  </div>
+</template>
+
+<script setup>
+import { useDraggable, useClipboard } from '@vueuse/core'
+import { useCalculatorStore } from '~/stores/calculator'
+
+const store = useCalculatorStore()
+const { copy, copied } = useClipboard()
+
+const el = ref(null)
+const { style } = useDraggable(el, {
+  initialValue: { x: window.innerWidth - 350, y: 150 },
+})
+
+const shouldResetDisplay = ref(false)
+const showHistory = ref(false)
+const previousValue = ref(null)
+const lastOperator = ref(null)
+
+// --- Logik ---
+const appendNumber = (num) => {
+  if (store.display === '0' || shouldResetDisplay.value) {
+    store.display = String(num)
+    shouldResetDisplay.value = false
+  } else {
+    store.display += String(num)
+  }
+}
+
+const addComma = () => {
+  if (!store.display.includes(',')) {
+    store.display += ','
+  }
+}
+
+const setOperator = (op) => {
+  previousValue.value = parseFloat(store.display.replace(',', '.'))
+  lastOperator.value = op
+  shouldResetDisplay.value = true
+}
+
+const calculate = () => {
+  if (lastOperator.value === null) return
+  const currentVal = parseFloat(store.display.replace(',', '.'))
+  const prevVal = previousValue.value
+  let result = 0
+
+  switch (lastOperator.value) {
+    case '+': result = prevVal + currentVal; break
+    case '-': result = prevVal - currentVal; break
+    case '*': result = prevVal * currentVal; break
+    case '/': result = currentVal !== 0 ? prevVal / currentVal : 0; break
+  }
+
+  const expression = `${prevVal} ${lastOperator.value} ${currentVal}`
+  const resultString = String(Number(result.toFixed(4))).replace('.', ',')
+
+  store.addHistory(expression, resultString)
+  store.display = resultString
+  lastOperator.value = null
+  shouldResetDisplay.value = true
+}
+
+const clear = () => {
+  store.display = '0'
+  previousValue.value = null
+  lastOperator.value = null
+}
+
+const applyTax = (percent) => {
+  const current = parseFloat(store.display.replace(',', '.'))
+  store.display = (current * (1 + percent / 100)).toFixed(2).replace('.', ',')
+}
+
+const removeTax = (percent) => {
+  const current = parseFloat(store.display.replace(',', '.'))
+  store.display = (current / (1 + percent / 100)).toFixed(2).replace('.', ',')
+}
+
+const addToSum = () => {
+  store.memory += parseFloat(store.display.replace(',', '.'))
+  shouldResetDisplay.value = true
+}
+
+const copyDisplay = () => {
+  copy(store.display)
+}
+
+const useHistoryItem = (val) => {
+  store.display = val
+  showHistory.value = false
+}
+
+// --- Shortcuts ---
+defineShortcuts({
+  '0': () => appendNumber(0),
+  '1': () => appendNumber(1),
+  '2': () => appendNumber(2),
+  '3': () => appendNumber(3),
+  '4': () => appendNumber(4),
+  '5': () => appendNumber(5),
+  '6': () => appendNumber(6),
+  '7': () => appendNumber(7),
+  '8': () => appendNumber(8),
+  '9': () => appendNumber(9),
+  'comma': addComma,
+  'plus': () => setOperator('+'),
+  'minus': () => setOperator('-'),
+  'enter': { usingInput: true, handler: calculate },
+  'backspace': () => {
+    store.display = store.display.length > 1 ? store.display.slice(0, -1) : '0'
+  },
+  // Escape schließt nun das Fenster via Store
+  'escape': {
+    usingInput: true,
+    whenever: [computed(() => store.isOpen)],
+    handler: () => { store.isOpen = false }
+  }
+})
+</script>
+
+<style scoped>
+.custom-scrollbar::-webkit-scrollbar {
+  width: 4px;
+}
+.custom-scrollbar::-webkit-scrollbar-track {
+  @apply bg-transparent;
+}
+.custom-scrollbar::-webkit-scrollbar-thumb {
+  @apply bg-gray-200 dark:bg-gray-700 rounded-full;
+}
+</style>
\ No newline at end of file
diff --git a/frontend/components/MainNav.vue b/frontend/components/MainNav.vue
index 1243b48..1556c7b 100644
--- a/frontend/components/MainNav.vue
+++ b/frontend/components/MainNav.vue
@@ -1,42 +1,39 @@
 <script setup>
-
 const route = useRoute()
 const auth = useAuthStore()
+const { has } = usePermission()
 
-const {has} = usePermission()
+// Lokaler State für den Taschenrechner
+const showCalculator = ref(false)
 
 const links = computed(() => {
   return [
-      ...(auth.profile?.pinned_on_navigation || []).map(pin => {
-        if(pin.type === "external") {
-          return {
-            label: pin.label,
-            to: pin.link,
-            icon: pin.icon,
-            target: "_blank",
-            pinned: true
-          }
-        }else if(pin.type === "standardEntity") {
-          return {
-            label: pin.label,
-            to: `/standardEntity/${pin.datatype}/show/${pin.id}`,
-            icon: pin.icon,
-            pinned: true
-          }
+    ...(auth.profile?.pinned_on_navigation || []).map(pin => {
+      if (pin.type === "external") {
+        return {
+          label: pin.label,
+          to: pin.link,
+          icon: pin.icon,
+          target: "_blank",
+          pinned: true
         }
-      }),
+      } else if (pin.type === "standardEntity") {
+        return {
+          label: pin.label,
+          to: `/standardEntity/${pin.datatype}/show/${pin.id}`,
+          icon: pin.icon,
+          pinned: true
+        }
+      }
+    }),
 
-    ... false ? [{
-      label: "Support Tickets",
-      to: "/support",
-      icon: "i-heroicons-rectangle-stack",
-    }] : [],
     {
       id: 'dashboard',
       label: "Dashboard",
       to: "/",
       icon: "i-heroicons-home"
-    }, {
+    },
+    {
       id: 'historyitems',
       label: "Logbuch",
       to: "/historyitems",
@@ -48,31 +45,11 @@ const links = computed(() => {
       icon: "i-heroicons-rectangle-stack",
       defaultOpen: false,
       children: [
-        ... has("tasks") ? [{
+        ...has("tasks") ? [{
           label: "Aufgaben",
           to: "/standardEntity/tasks",
           icon: "i-heroicons-rectangle-stack"
         }] : [],
-        /*... true ? [{
-          label: "Plantafel",
-          to: "/calendar/timeline",
-          icon: "i-heroicons-calendar-days"
-        }] : [],
-        ... true ? [{
-          label: "Kalender",
-          to: "/calendar/grid",
-          icon: "i-heroicons-calendar-days"
-        }] : [],
-        ... true ? [{
-          label: "Termine",
-          to: "/standardEntity/events",
-          icon: "i-heroicons-calendar-days"
-        }] : [],*/
-        /*{
-          label: "Dateien",
-          to: "/files",
-          icon: "i-heroicons-document"
-        },*/
       ]
     },
     {
@@ -84,12 +61,12 @@ const links = computed(() => {
           label: "Dateien",
           to: "/files",
           icon: "i-heroicons-document"
-        },{
+        }, {
           label: "Anschreiben",
           to: "/createdletters",
           icon: "i-heroicons-document",
           disabled: true
-        },{
+        }, {
           label: "Boxen",
           to: "/standardEntity/documentboxes",
           icon: "i-heroicons-archive-box",
@@ -113,62 +90,44 @@ const links = computed(() => {
           to: "/email/new",
           icon: "i-heroicons-envelope",
           disabled: true
-        }/*, {
-          label: "Logbücher",
-          to: "/communication/historyItems",
-          icon: "i-heroicons-book-open"
-        }, {
-          label: "Chats",
-          to: "/chats",
-          icon: "i-heroicons-chat-bubble-left"
-        }*/
+        }
       ]
     },
-    ... (has("customers") || has("vendors") || has("contacts")) ? [{
+    ...(has("customers") || has("vendors") || has("contacts")) ? [{
       label: "Kontakte",
       defaultOpen: false,
       icon: "i-heroicons-user-group",
       children: [
-        ... has("customers") ? [{
+        ...has("customers") ? [{
           label: "Kunden",
           to: "/standardEntity/customers",
           icon: "i-heroicons-user-group"
         }] : [],
-        ... has("vendors") ? [{
+        ...has("vendors") ? [{
           label: "Lieferanten",
           to: "/standardEntity/vendors",
           icon: "i-heroicons-truck"
         }] : [],
-        ... has("contacts") ? [{
+        ...has("contacts") ? [{
           label: "Ansprechpartner",
           to: "/standardEntity/contacts",
           icon: "i-heroicons-user-group"
         }] : [],
       ]
-    },] : [],
+    }] : [],
     {
       label: "Mitarbeiter",
-      defaultOpen:false,
+      defaultOpen: false,
       icon: "i-heroicons-user-group",
       children: [
-        ... true ? [{
+        ...true ? [{
           label: "Zeiten",
           to: "/staff/time",
           icon: "i-heroicons-clock",
         }] : [],
-        /*... has("absencerequests") ? [{
-          label: "Abwesenheiten",
-          to: "/standardEntity/absencerequests",
-          icon: "i-heroicons-document-text"
-        }] : [],*/
-        /*{
-          label: "Fahrten",
-          to: "/trackingTrips",
-          icon: "i-heroicons-map"
-        },*/
       ]
     },
-    ... [{
+    ...[{
       label: "Buchhaltung",
       defaultOpen: false,
       icon: "i-heroicons-chart-bar-square",
@@ -177,23 +136,23 @@ const links = computed(() => {
           label: "Ausgangsbelege",
           to: "/createDocument",
           icon: "i-heroicons-document-text"
-        },{
+        }, {
           label: "Serienvorlagen",
           to: "/createDocument/serialInvoice",
           icon: "i-heroicons-document-text"
-        },{
+        }, {
           label: "Eingangsbelege",
           to: "/incomingInvoices",
           icon: "i-heroicons-document-text",
-        },{
+        }, {
           label: "Kostenstellen",
           to: "/standardEntity/costcentres",
           icon: "i-heroicons-document-currency-euro"
-        },{
+        }, {
           label: "Buchungskonten",
           to: "/accounts",
           icon: "i-heroicons-document-text",
-        },{
+        }, {
           label: "zusätzliche Buchungskonten",
           to: "/standardEntity/ownaccounts",
           icon: "i-heroicons-document-text"
@@ -205,48 +164,39 @@ const links = computed(() => {
         },
       ]
     }],
-    ... has("inventory") ? [{
+    ...has("inventory") ? [{
       label: "Lager",
       icon: "i-heroicons-puzzle-piece",
       defaultOpen: false,
       children: [
-        /*{
-          label: "Vorgänge",
-          to: "/inventory",
-          icon: "i-heroicons-square-3-stack-3d"
-        },{
-          label: "Bestände",
-          to: "/inventory/stocks",
-          icon: "i-heroicons-square-3-stack-3d"
-        },*/
-        ... has("spaces") ? [{
+        ...has("spaces") ? [{
           label: "Lagerplätze",
           to: "/standardEntity/spaces",
           icon: "i-heroicons-square-3-stack-3d"
         }] : [],
       ]
-    },] : [],
+    }] : [],
     {
       label: "Stammdaten",
       defaultOpen: false,
       icon: "i-heroicons-clipboard-document",
       children: [
-        ... has("products") ? [{
+        ...has("products") ? [{
           label: "Artikel",
           to: "/standardEntity/products",
           icon: "i-heroicons-puzzle-piece"
         }] : [],
-        ... has("productcategories") ? [{
+        ...has("productcategories") ? [{
           label: "Artikelkategorien",
           to: "/standardEntity/productcategories",
           icon: "i-heroicons-puzzle-piece"
         }] : [],
-        ... has("services") ? [{
+        ...has("services") ? [{
           label: "Leistungen",
           to: "/standardEntity/services",
           icon: "i-heroicons-wrench-screwdriver"
         }] : [],
-        ... has("servicecategories") ? [{
+        ...has("servicecategories") ? [{
           label: "Leistungskategorien",
           to: "/standardEntity/servicecategories",
           icon: "i-heroicons-wrench-screwdriver"
@@ -261,17 +211,17 @@ const links = computed(() => {
           to: "/standardEntity/hourrates",
           icon: "i-heroicons-user-group"
         },
-        ... has("vehicles") ? [{
+        ...has("vehicles") ? [{
           label: "Fahrzeuge",
           to: "/standardEntity/vehicles",
           icon: "i-heroicons-truck"
         }] : [],
-        ... has("inventoryitems") ? [{
+        ...has("inventoryitems") ? [{
           label: "Inventar",
           to: "/standardEntity/inventoryitems",
           icon: "i-heroicons-puzzle-piece"
         }] : [],
-        ... has("inventoryitems") ? [{
+        ...has("inventoryitems") ? [{
           label: "Inventargruppen",
           to: "/standardEntity/inventoryitemgroups",
           icon: "i-heroicons-puzzle-piece"
@@ -279,26 +229,21 @@ const links = computed(() => {
       ]
     },
 
-    ... has("projects") ? [{
+    ...has("projects") ? [{
       label: "Projekte",
       to: "/standardEntity/projects",
       icon: "i-heroicons-clipboard-document-check"
-    },] : [],
-    ... has("contracts") ? [{
+    }] : [],
+    ...has("contracts") ? [{
       label: "Verträge",
       to: "/standardEntity/contracts",
       icon: "i-heroicons-clipboard-document"
     }] : [],
-    ... has("plants") ? [{
+    ...has("plants") ? [{
       label: "Objekte",
       to: "/standardEntity/plants",
       icon: "i-heroicons-clipboard-document"
-    },] : [],
-    /*... has("checks") ? [{
-      label: "Überprüfungen",
-      to: "/standardEntity/checks",
-      icon: "i-heroicons-magnifying-glass"
-    },] : [],*/
+    }] : [],
     {
       label: "Einstellungen",
       defaultOpen: false,
@@ -308,67 +253,57 @@ const links = computed(() => {
           label: "Nummernkreise",
           to: "/settings/numberRanges",
           icon: "i-heroicons-clipboard-document-list",
-        },/*{
-          label: "Rollen",
-          to: "/roles",
-          icon: "i-heroicons-key"
-        },*/{
+        }, {
           label: "E-Mail Konten",
           to: "/settings/emailaccounts",
           icon: "i-heroicons-envelope",
-        },{
+        }, {
           label: "Bankkonten",
           to: "/settings/banking",
           icon: "i-heroicons-currency-euro",
-        },{
+        }, {
           label: "Textvorlagen",
           to: "/settings/texttemplates",
           icon: "i-heroicons-clipboard-document-list",
-        },/*{
-          label: "Eigene Felder",
-          to: "/settings/ownfields",
-          icon: "i-heroicons-clipboard-document-list"
-        },*/{
+        }, {
           label: "Firmeneinstellungen",
           to: "/settings/tenant",
           icon: "i-heroicons-building-office",
-        },{
+        }, {
           label: "Projekttypen",
           to: "/projecttypes",
           icon: "i-heroicons-clipboard-document-list",
-        },{
+        }, {
           label: "Export",
           to: "/export",
           icon: "i-heroicons-clipboard-document-list"
         }
       ]
-    }
+    },
   ]
 })
 
-// nur Items mit Children → für Accordion
 const accordionItems = computed(() =>
     links.value.filter(item => Array.isArray(item.children) && item.children.length > 0)
 )
 
-// nur Items ohne Children → als Buttons
 const buttonItems = computed(() =>
     links.value.filter(item => !item.children || item.children.length === 0)
 )
 </script>
 
 <template>
-  <!-- Standalone Buttons -->
   <div class="flex flex-col gap-1">
     <UButton
         v-for="item in buttonItems"
         :key="item.label"
-        :variant="item.pinned ? 'ghost' : 'ghost'"
+        variant="ghost"
         :color="(item.to && route.path === item.to) ? 'primary' : (item.pinned ? 'amber' : 'gray')"
         :icon="item.pinned ? 'i-heroicons-star' : item.icon"
         class="w-full"
         :to="item.to"
         :target="item.target"
+        @click="item.click ? item.click() : null"
     >
       <UIcon
           v-if="item.pinned"
@@ -378,8 +313,9 @@ const buttonItems = computed(() =>
       {{ item.label }}
     </UButton>
   </div>
-  <UDivider/>
-  <!-- Accordion für die Items mit Children -->
+
+  <UDivider class="my-2"/>
+
   <UAccordion
       :items="accordionItems"
       :multiple="false"
@@ -387,7 +323,7 @@ const buttonItems = computed(() =>
   >
     <template #default="{ item, open }">
       <UButton
-          :variant="'ghost'"
+          variant="ghost"
           :color="(item.children?.some(c => route.path.includes(c.to))) ? 'primary' : 'gray'"
           :icon="item.icon"
           class="w-full"
@@ -415,56 +351,13 @@ const buttonItems = computed(() =>
             :to="child.to"
             :target="child.target"
             :disabled="child.disabled"
+            @click="child.click ? child.click() : null"
         >
           {{ child.label }}
         </UButton>
       </div>
     </template>
   </UAccordion>
-<!--  <UAccordion
-      :items="links"
-      :multiple="false"
-  >
-    <template #default="{ item, index, open }">
-      <UButton
-          :variant="item.pinned ? 'ghost' : 'ghost'"
-          :color="(item.to && route.path === item.to) || (item.children?.some(c => route.path.includes(c.to))) ? 'primary' : (item.pinned ? 'amber' : 'gray')"
-          :icon="item.pinned ? 'i-heroicons-star' : item.icon"
-          class="w-full"
-          :to="item.to"
-          :target="item.target"
-      >
-        <UIcon
-            v-if="item.pinned"
-            :name="item.icon" class="w-5 h-5 me-2" />
-        {{ item.label }}
-
-        <template v-if="item.children" #trailing>
-          <UIcon
-              name="i-heroicons-chevron-right-20-solid"
-              class="w-5 h-5 ms-auto transform transition-transform duration-200"
-              :class="[open && 'rotate-90']"
-          />
-        </template>
-      </UButton>
-    </template>
-
-    <template #item="{ item }">
-      <div class="flex flex-col" v-if="item.children?.length > 0">
-        <UButton
-            v-for="child in item.children"
-            :key="child.label"
-            variant="ghost"
-            :color="child.to === route.path ? 'primary' : 'gray'"
-            :icon="child.icon"
-            class="ml-4"
-            :to="child.to"
-            :target="child.target"
-        >
-          {{ child.label }}
-        </UButton>
-      </div>
-    </template>
-  </UAccordion>-->
 
+  <Calculator v-if="showCalculator" v-model="showCalculator"/>
 </template>
\ No newline at end of file
diff --git a/frontend/layouts/default.vue b/frontend/layouts/default.vue
index 6139269..af28f01 100644
--- a/frontend/layouts/default.vue
+++ b/frontend/layouts/default.vue
@@ -1,21 +1,20 @@
 <script setup>
-
-
 import MainNav from "~/components/MainNav.vue";
 import dayjs from "dayjs";
 import GlobalMessages from "~/components/GlobalMessages.vue";
 import TenantDropdown from "~/components/TenantDropdown.vue";
 import LabelPrinterButton from "~/components/LabelPrinterButton.vue";
+import {useCalculatorStore} from '~/stores/calculator'
 
 const dataStore = useDataStore()
 const colorMode = useColorMode()
-const { isHelpSlideoverOpen } = useDashboard()
+const {isHelpSlideoverOpen} = useDashboard()
 const router = useRouter()
 const route = useRoute()
 
 const auth = useAuthStore()
 const labelPrinter = useLabelPrinterStore()
-
+const calculatorStore = useCalculatorStore()
 
 const month = dayjs().format("MM")
 
@@ -24,91 +23,108 @@ const actions = [
     id: 'new-customer',
     label: 'Kunde hinzufügen',
     icon: 'i-heroicons-user-group',
-    to: "/customers/create" ,
+    to: "/customers/create",
   },
   {
     id: 'new-vendor',
     label: 'Lieferant hinzufügen',
     icon: 'i-heroicons-truck',
-    to: "/vendors/create" ,
+    to: "/vendors/create",
   },
   {
     id: 'new-contact',
     label: 'Ansprechpartner hinzufügen',
     icon: 'i-heroicons-user-group',
-    to: "/contacts/create" ,
+    to: "/contacts/create",
   },
   {
     id: 'new-task',
     label: 'Aufgabe hinzufügen',
     icon: 'i-heroicons-rectangle-stack',
-    to: "/tasks/create" ,
+    to: "/tasks/create",
   },
   {
     id: 'new-plant',
     label: 'Objekt hinzufügen',
     icon: 'i-heroicons-clipboard-document',
-    to: "/plants/create" ,
+    to: "/plants/create",
   },
   {
     id: 'new-product',
     label: 'Artikel hinzufügen',
     icon: 'i-heroicons-puzzle-piece',
-    to: "/products/create" ,
+    to: "/products/create",
   },
   {
     id: 'new-project',
     label: 'Projekt hinzufügen',
     icon: 'i-heroicons-clipboard-document-check',
-    to: "/projects/create" ,
+    to: "/projects/create",
   }
 ]
 
-
 const groups = computed(() => [
-    {
-      key: 'actions',
-      commands: actions
-    },{
-      key: "customers",
-      label: "Kunden",
-      commands: dataStore.customers.map(item => { return {id: item.id, label: item.name, to: `/customers/show/${item.id}`}})
-    },{
-      key: "vendors",
-      label: "Lieferanten",
-      commands: dataStore.vendors.map(item => { return {id: item.id, label: item.name, to: `/vendors/show/${item.id}`}})
-    },{
-      key: "contacts",
-      label: "Ansprechpartner",
-      commands: dataStore.contacts.map(item => { return {id: item.id, label: item.fullName, to: `/contacts/show/${item.id}`}})
-    },{
-      key: "products",
-      label: "Artikel",
-      commands: dataStore.products.map(item => { return {id: item.id, label: item.name, to: `/products/show/${item.id}`}})
-    },{
-      key: "tasks",
-      label: "Aufgaben",
-      commands: dataStore.tasks.map(item => { return {id: item.id, label: item.name, to: `/tasks/show/${item.id}`}})
-    },{
-      key: "plants",
-      label: "Objekte",
-      commands: dataStore.plants.map(item => { return {id: item.id, label: item.name, to: `/plants/show/${item.id}`}})
-    },{
-      key: "projects",
-      label: "Projekte",
-      commands: dataStore.projects.map(item => { return {id: item.id, label: item.name, to: `/projects/show/${item.id}`}})
-    }
-    ].filter(Boolean))
-const footerLinks = [
-    /*{
-  label: 'Invite people',
-  icon: 'i-heroicons-plus',
-  to: '/settings/members'
-}, */{
-  label: 'Hilfe & Info',
-  icon: 'i-heroicons-question-mark-circle',
-  click: () => isHelpSlideoverOpen.value = true
-}]
+  {
+    key: 'actions',
+    commands: actions
+  }, {
+    key: "customers",
+    label: "Kunden",
+    commands: dataStore.customers.map(item => {
+      return {id: item.id, label: item.name, to: `/customers/show/${item.id}`}
+    })
+  }, {
+    key: "vendors",
+    label: "Lieferanten",
+    commands: dataStore.vendors.map(item => {
+      return {id: item.id, label: item.name, to: `/vendors/show/${item.id}`}
+    })
+  }, {
+    key: "contacts",
+    label: "Ansprechpartner",
+    commands: dataStore.contacts.map(item => {
+      return {id: item.id, label: item.fullName, to: `/contacts/show/${item.id}`}
+    })
+  }, {
+    key: "products",
+    label: "Artikel",
+    commands: dataStore.products.map(item => {
+      return {id: item.id, label: item.name, to: `/products/show/${item.id}`}
+    })
+  }, {
+    key: "tasks",
+    label: "Aufgaben",
+    commands: dataStore.tasks.map(item => {
+      return {id: item.id, label: item.name, to: `/tasks/show/${item.id}`}
+    })
+  }, {
+    key: "plants",
+    label: "Objekte",
+    commands: dataStore.plants.map(item => {
+      return {id: item.id, label: item.name, to: `/plants/show/${item.id}`}
+    })
+  }, {
+    key: "projects",
+    label: "Projekte",
+    commands: dataStore.projects.map(item => {
+      return {id: item.id, label: item.name, to: `/projects/show/${item.id}`}
+    })
+  }
+].filter(Boolean))
+
+// --- Footer Links nutzen jetzt den zentralen Calculator Store ---
+const footerLinks = computed(() => [
+  {
+    label: 'Taschenrechner',
+    icon: 'i-heroicons-calculator',
+    click: () => calculatorStore.toggle()
+  },
+  {
+    label: 'Hilfe & Info',
+    icon: 'i-heroicons-question-mark-circle',
+    click: () => isHelpSlideoverOpen.value = true
+  }
+])
 
 </script>
 
@@ -130,24 +146,24 @@ const footerLinks = [
               v-else
           />
           <div class="flex justify-center mb-6">
-            <UIcon name="i-heroicons-exclamation-triangle-solid" class="w-16 h-16 text-yellow-500" />
+            <UIcon name="i-heroicons-exclamation-triangle-solid" class="w-16 h-16 text-yellow-500"/>
           </div>
 
           <h1 class="text-2xl font-bold text-gray-900 dark:text-white mb-4">
             Wartungsarbeiten
           </h1>
           <p class="text-gray-600 dark:text-gray-300 mb-8">
-            Dieser FEDEO Mandant wird derzeit gewartet. Bitte versuche es in einigen Minuten erneut oder verwende einen anderen Mandanten.
+            Dieser FEDEO Mandant wird derzeit gewartet. Bitte versuche es in einigen Minuten erneut oder verwende einen
+            anderen Mandanten.
           </p>
           <div class="mx-auto text-left flex flex-row justify-between my-3" v-for="tenant in auth.tenants">
-            {{tenant.name}}
+            {{ tenant.name }}
             <UButton
                 :disabled="tenant.locked"
                 @click="auth.switchTenant(tenant.id)"
-            >Wählen</UButton>
+            >Wählen
+            </UButton>
           </div>
-
-
         </UCard>
       </UContainer>
     </div>
@@ -167,7 +183,7 @@ const footerLinks = [
               v-else
           />
           <div class="flex justify-center mb-6">
-            <UIcon name="i-heroicons-exclamation-triangle-solid" class="w-16 h-16 text-yellow-500" />
+            <UIcon name="i-heroicons-exclamation-triangle-solid" class="w-16 h-16 text-yellow-500"/>
           </div>
 
           <h1 class="text-2xl font-bold text-gray-900 dark:text-white mb-4">
@@ -176,8 +192,6 @@ const footerLinks = [
           <p class="text-gray-600 dark:text-gray-300 mb-8">
             FEDEO wird derzeit gewartet. Bitte versuche es in einigen Minuten erneut.
           </p>
-
-
         </UCard>
       </UContainer>
     </div>
@@ -197,32 +211,33 @@ const footerLinks = [
               v-else
           />
           <div class="flex justify-center mb-6">
-            <UIcon name="i-heroicons-credit-card" class="w-16 h-16 text-red-600" />
+            <UIcon name="i-heroicons-credit-card" class="w-16 h-16 text-red-600"/>
           </div>
 
           <h1 class="text-2xl font-bold text-gray-900 dark:text-white mb-4">
             Kein Aktives Abonnement für diesen Mandant.
           </h1>
           <p class="text-gray-600 dark:text-gray-300 mb-8">
-            Bitte wenden Sie sich an den FEDEO Support um ein Abonnement zu erhalten oder verwenden Sie einen anderen Mandanten.
+            Bitte wenden Sie sich an den FEDEO Support um ein Abonnement zu erhalten oder verwenden Sie einen anderen
+            Mandanten.
           </p>
           <div class="mx-auto text-left flex flex-row justify-between my-3" v-for="tenant in auth.tenants">
-            {{tenant.name}}
+            {{ tenant.name }}
             <UButton
                 :disabled="tenant.locked"
                 @click="auth.switchTenant(tenant.id)"
-            >Wählen</UButton>
+            >Wählen
+            </UButton>
           </div>
-
-
         </UCard>
       </UContainer>
     </div>
-    <UDashboardLayout class="safearea" v-else  >
+    <UDashboardLayout class="safearea" v-else>
       <UDashboardPanel :width="250" :resizable="{ min: 200, max: 300 }" collapsible>
-        <UDashboardNavbar style="margin-top: env(safe-area-inset-top, 10px) !important;" :class="['!border-transparent']" :ui="{ left: 'flex-1' }">
+        <UDashboardNavbar style="margin-top: env(safe-area-inset-top, 10px) !important;"
+                          :class="['!border-transparent']" :ui="{ left: 'flex-1' }">
           <template #left>
-            <TenantDropdown class="w-full" />
+            <TenantDropdown class="w-full"/>
           </template>
         </UDashboardNavbar>
 
@@ -230,24 +245,17 @@ const footerLinks = [
 
           <MainNav/>
 
-          <div class="flex-1" />
-
+          <div class="flex-1"/>
 
           <template #footer>
             <div class="flex flex-col gap-3 w-full">
 
-
-              <UColorModeButton />
+              <UColorModeButton/>
               <LabelPrinterButton/>
 
+              <UDashboardSidebarLinks :links="footerLinks"/>
 
-
-              <!-- Footer Links -->
-              <UDashboardSidebarLinks :links="footerLinks" />
-
-
-
-              <UDivider class="sticky bottom-0" />
+              <UDivider class="sticky bottom-0"/>
               <UserDropdown style="margin-bottom: env(safe-area-inset-bottom, 10px) !important;"/>
             </div>
           </template>
@@ -256,14 +264,14 @@ const footerLinks = [
 
       <UDashboardPage>
         <UDashboardPanel grow>
-          <slot />
+          <slot/>
         </UDashboardPanel>
       </UDashboardPage>
 
-
-
       <HelpSlideover/>
 
+      <Calculator v-if="calculatorStore.isOpen"/>
+
     </UDashboardLayout>
   </div>
 
@@ -278,37 +286,32 @@ const footerLinks = [
         v-if="month === '12'"
     />
     <UColorModeImage
-      light="/Logo.png"
-      dark="/Logo_Dark.png"
-      class="w-1/3 mx-auto my-10"
-      v-else
+        light="/Logo.png"
+        dark="/Logo_Dark.png"
+        class="w-1/3 mx-auto my-10"
+        v-else
     />
 
     <div v-if="!auth.activeTenant" class="w-1/2 mx-auto text-center">
-        <!-- Tenant Selection      -->
-        <h3 class="text-center font-bold text-2xl mb-5">Kein Aktiver Mandant. Bitte wählen Sie ein Mandant.</h3>
-        <div class="mx-auto w-1/2 flex flex-row justify-between my-3" v-for="tenant in auth.tenants">
-          <span class="text-left">{{tenant.name}}</span>
-          <UButton
-            @click="auth.switchTenant(tenant.id)"
-          >Wählen</UButton>
-        </div>
+      <h3 class="text-center font-bold text-2xl mb-5">Kein Aktiver Mandant. Bitte wählen Sie ein Mandant.</h3>
+      <div class="mx-auto w-1/2 flex flex-row justify-between my-3" v-for="tenant in auth.tenants">
+        <span class="text-left">{{ tenant.name }}</span>
         <UButton
-            variant="outline"
-            color="rose"
+            @click="auth.switchTenant(tenant.id)"
+        >Wählen
+        </UButton>
+      </div>
+      <UButton
+          variant="outline"
+          color="rose"
           @click="auth.logout()"
-        >Abmelden</UButton>
-
-
+      >Abmelden
+      </UButton>
     </div>
     <div v-else>
-      <UProgress animation="carousel" class="w-3/4 mx-auto mt-10" />
+      <UProgress animation="carousel" class="w-3/4 mx-auto mt-10"/>
     </div>
 
   </div>
 
-</template>
-
-<style scoped>
-
-</style>
\ No newline at end of file
+</template>
\ No newline at end of file
diff --git a/frontend/stores/calculator.ts b/frontend/stores/calculator.ts
new file mode 100644
index 0000000..ece9b51
--- /dev/null
+++ b/frontend/stores/calculator.ts
@@ -0,0 +1,40 @@
+import { defineStore } from 'pinia'
+
+export const useCalculatorStore = defineStore('calculator', () => {
+    const tempStore = useTempStore()
+
+    // Initialisierung aus dem TempStore
+    const isOpen = ref(false)
+    const display = computed({
+        get: () => tempStore.settings?.calculator?.display || '0',
+        set: (val) => tempStore.modifySettings('calculator', { ...tempStore.settings.calculator, display: val })
+    })
+
+    const memory = computed({
+        get: () => tempStore.settings?.calculator?.memory || 0,
+        set: (val) => tempStore.modifySettings('calculator', { ...tempStore.settings.calculator, memory: val })
+    })
+
+    const history = computed({
+        get: () => tempStore.filters?.calculator?.history || [],
+        set: (val) => tempStore.modifyFilter('calculator', 'history', val)
+    })
+
+    function toggle() {
+        isOpen.value = !isOpen.value
+    }
+
+    function addHistory(expression: string, result: string) {
+        const newHistory = [{ expression, result }, ...history.value].slice(0, 10)
+        history.value = newHistory
+    }
+
+    return {
+        isOpen,
+        display,
+        memory,
+        history,
+        toggle,
+        addHistory
+    }
+})
\ No newline at end of file