diff --git a/src/frontend/components/circuit-tree-editor.tsx b/src/frontend/components/circuit-tree-editor.tsx
index b214d60..3ecaf16 100644
--- a/src/frontend/components/circuit-tree-editor.tsx
+++ b/src/frontend/components/circuit-tree-editor.tsx
@@ -27,6 +27,7 @@ import {
   buildDeviceRowEditPatch,
   defaultVisibleColumnKeys,
   deviceFieldKeys,
+  formatCellValue,
   formatPhaseTypeLabel,
   formatValue,
   getCircuitSectionLabel,
@@ -4392,7 +4393,7 @@ export function CircuitTreeEditor(props: { projectId: string; circuitListId: str
                             }}
                           />
                         ) : (
-                          formatValue(cell.value, column.key)
+                          formatCellValue(cell.value, column.key)
                         )}
                       </td>
                     );
diff --git a/src/frontend/components/circuit-tree-preview.tsx b/src/frontend/components/circuit-tree-preview.tsx
index cd93739..207dee4 100644
--- a/src/frontend/components/circuit-tree-preview.tsx
+++ b/src/frontend/components/circuit-tree-preview.tsx
@@ -5,6 +5,7 @@ import { Fragment } from "react";
 import { getCircuitTree } from "../utils/api";
 import type { CircuitTreeCircuitDto, CircuitTreeResponseDto } from "../types";
 import {
+  formatCellValue,
   formatValue,
   getCircuitSectionLabel,
 } from "../utils/circuit-grid-model";
@@ -112,7 +113,7 @@ function SectionRows(props: { section: CircuitTreeResponseDto["sections"][number
               <td>{circuit.displayName?.trim() || "Reserve"}</td>
               <td colSpan={11}>-</td>
               <td className="text-end">
-                {formatValue(circuit.circuitTotalPower, "circuitTotalPower")}
+                {formatCellValue(circuit.circuitTotalPower, "circuitTotalPower")}
               </td>
               <td>{circuit.protectionDevice?.type ?? "-"}</td>
               <td className="text-end">
@@ -140,13 +141,13 @@ function SectionRows(props: { section: CircuitTreeResponseDto["sections"][number
               <td>{row.level ?? "-"}</td>
               <td>{row.roomNumberSnapshot ?? "-"}</td>
               <td>{row.roomNameSnapshot ?? "-"}</td>
-              <td className="text-end">{formatValue(row.quantity, "quantity")}</td>
-              <td className="text-end">{formatValue(row.powerPerUnit, "powerPerUnit")}</td>
+              <td className="text-end">{formatCellValue(row.quantity, "quantity")}</td>
+              <td className="text-end">{formatCellValue(row.powerPerUnit, "powerPerUnit")}</td>
               <td className="text-end">
                 {formatValue(row.simultaneityFactor, "simultaneityFactor")}
               </td>
               <td className="text-end">{formatValue(row.cosPhi, "cosPhi")}</td>
-              <td className="text-end">{formatValue(row.rowTotalPower, "rowTotalPower")}</td>
+              <td className="text-end">{formatCellValue(row.rowTotalPower, "rowTotalPower")}</td>
               <td>{circuit.protectionDevice?.type ?? "-"}</td>
               <td className="text-end">
                 {formatValue(circuit.protectionDevice?.ratedCurrentA, "protectionRatedCurrent")}
@@ -167,7 +168,7 @@ function SectionRows(props: { section: CircuitTreeResponseDto["sections"][number
               <td>{renderCircuitSummaryLabel(circuit)}</td>
               <td colSpan={11}>-</td>
               <td className="text-end">
-                {formatValue(circuit.circuitTotalPower, "circuitTotalPower")}
+                {formatCellValue(circuit.circuitTotalPower, "circuitTotalPower")}
               </td>
               <td>{circuit.protectionDevice?.type ?? "-"}</td>
               <td className="text-end">
@@ -190,13 +191,13 @@ function SectionRows(props: { section: CircuitTreeResponseDto["sections"][number
                 <td>{row.level ?? "-"}</td>
                 <td>{row.roomNumberSnapshot ?? "-"}</td>
                 <td>{row.roomNameSnapshot ?? "-"}</td>
-                <td className="text-end">{formatValue(row.quantity, "quantity")}</td>
-                <td className="text-end">{formatValue(row.powerPerUnit, "powerPerUnit")}</td>
+                <td className="text-end">{formatCellValue(row.quantity, "quantity")}</td>
+                <td className="text-end">{formatCellValue(row.powerPerUnit, "powerPerUnit")}</td>
                 <td className="text-end">
                   {formatValue(row.simultaneityFactor, "simultaneityFactor")}
                 </td>
                 <td className="text-end">{formatValue(row.cosPhi, "cosPhi")}</td>
-                <td className="text-end">{formatValue(row.rowTotalPower, "rowTotalPower")}</td>
+                <td className="text-end">{formatCellValue(row.rowTotalPower, "rowTotalPower")}</td>
                 <td>-</td>
                 <td className="text-end">-</td>
                 <td>-</td>
diff --git a/src/frontend/utils/circuit-grid-model.ts b/src/frontend/utils/circuit-grid-model.ts
index 47e7189..bdb2fae 100644
--- a/src/frontend/utils/circuit-grid-model.ts
+++ b/src/frontend/utils/circuit-grid-model.ts
@@ -351,6 +351,24 @@ export function formatValue(value: GridValue, key?: CellKey): string {
   return String(value);
 }
 
+export function formatCellValue(value: GridValue, key: CellKey): string {
+  const formatted = formatValue(value, key);
+  if (formatted === "-" || typeof value !== "number") {
+    return formatted;
+  }
+  if (key === "quantity") {
+    return `${formatted} St.`;
+  }
+  if (
+    key === "powerPerUnit" ||
+    key === "rowTotalPower" ||
+    key === "circuitTotalPower"
+  ) {
+    return `${formatted} kW`;
+  }
+  return formatted;
+}
+
 export function formatPhaseTypeLabel(value: string): string {
   if (value === "single_phase") {
     return "1-phasig";
@@ -378,7 +396,7 @@ export function parseNumeric(cellKey: CellKey, draft: string): number | undefine
   if (trimmed === "") {
     return undefined;
   }
-  const parsed = Number(trimmed);
+  const parsed = Number(trimmed.replace(",", "."));
   if (Number.isNaN(parsed)) {
     throw new Error(`Ungültiger Zahlenwert in ${cellKey}`);
   }
diff --git a/tests/circuit-grid-model.test.ts b/tests/circuit-grid-model.test.ts
index 6dbfef8..1e82a7c 100644
--- a/tests/circuit-grid-model.test.ts
+++ b/tests/circuit-grid-model.test.ts
@@ -5,6 +5,7 @@ import {
   buildCircuitEditPatch,
   buildDeviceRowEditPatch,
   formatValue,
+  formatCellValue,
   getCircuitSectionLabel,
   getProjectColumnLayoutStorageKey,
   isGridEditorControlTarget,
@@ -173,6 +174,10 @@ describe("circuit grid model", () => {
     assert.equal(formatValue(16, "protectionRatedCurrent"), "16");
     assert.equal(formatValue("single_phase", "phaseType"), "1-phasig");
     assert.equal(formatValue("three_phase", "phaseType"), "3-phasig");
+    assert.equal(formatCellValue(2, "quantity"), "2 St.");
+    assert.equal(formatCellValue(0.123456, "powerPerUnit"), "0,123 kW");
+    assert.equal(formatCellValue(1.25, "rowTotalPower"), "1,25 kW");
+    assert.equal(formatCellValue(undefined, "circuitTotalPower"), "-");
   });
 
   it("uses circuit display values for block sorting and falls back to the first device", () => {
@@ -183,6 +188,7 @@ describe("circuit grid model", () => {
 
   it("parses numeric drafts and rejects invalid values", () => {
     assert.equal(parseNumeric("quantity", " 2.5 "), 2.5);
+    assert.equal(parseNumeric("powerPerUnit", " 1,25 "), 1.25);
     assert.equal(parseNumeric("quantity", ""), undefined);
     assert.throws(() => parseNumeric("quantity", "two"), /Ungültiger Zahlenwert/);
   });