diff --git a/src/components/ElementDetail.tsx b/src/components/ElementDetail.tsx
index 78342b5..830a766 100644
--- a/src/components/ElementDetail.tsx
+++ b/src/components/ElementDetail.tsx
@@ -6,7 +6,12 @@ import { FieldLabel, MoneyField, NumberField, SelectField } from "@/components/F
 import { formatChf } from "@/lib/format";
 import { api } from "@/lib/api-client";
 import { CATEGORY_LABELS, num } from "@/lib/elements";
-import { PILLAR_3A_MAX_ANNUAL } from "@/lib/constants";
+import {
+  DEFAULT_CAPITAL_TAX_RATE,
+  DEFAULT_PK_CONVERSION_RATE,
+  DEFAULT_PROPERTY_GAINS_TAX_RATE,
+  PILLAR_3A_MAX_ANNUAL,
+} from "@/lib/constants";
 import type { ElementCategory, PhaseData, TransitionData } from "@/lib/elements";
 
 export interface CellContext {
@@ -336,12 +341,12 @@ export function ElementTransitionFields({
                 label="Umwandlungssatz (%)"
                 help="Jaehrliche Rente = verrentetes Kapital x Umwandlungssatz."
                 step={0.1}
-                value={num(td.conversionRate, 6)}
+                value={num(td.conversionRate, DEFAULT_PK_CONVERSION_RATE)}
                 onChange={(v) => setT({ conversionRate: v })}
               />
             )}
             {(mode === "CAPITAL" || mode === "COMBI") && (
-              <NumberField label="Kapitalbezugssteuer (%)" step={0.5} value={num(td.capitalTaxRate, 8)} onChange={(v) => setT({ capitalTaxRate: v })} />
+              <NumberField label="Kapitalbezugssteuer (%)" step={0.5} value={num(td.capitalTaxRate, DEFAULT_CAPITAL_TAX_RATE)} onChange={(v) => setT({ capitalTaxRate: v })} />
             )}
             {mode === "COMBI" && (
               <MoneyField
@@ -363,7 +368,7 @@ export function ElementTransitionFields({
             label="Kapitalbezugssteuer (%)"
             help="Die Saeule 3a wird bei Pensionierung vollstaendig bezogen."
             step={0.5}
-            value={num(td.capitalTaxRate, 8)}
+            value={num(td.capitalTaxRate, DEFAULT_CAPITAL_TAX_RATE)}
             onChange={(v) => setT({ capitalTaxRate: v })}
           />
         );
@@ -385,7 +390,7 @@ export function ElementTransitionFields({
           {decision === "SELL" && (
             <>
               <MoneyField label="Verkaufspreis (CHF)" value={num(td.salePrice)} onChange={(v) => setT({ salePrice: v })} />
-              <NumberField label="Grundstueckgewinnsteuer (%)" step={1} value={num(td.saleTaxRate, 20)} onChange={(v) => setT({ saleTaxRate: v })} />
+              <NumberField label="Grundstueckgewinnsteuer (%)" step={1} value={num(td.saleTaxRate, DEFAULT_PROPERTY_GAINS_TAX_RATE)} onChange={(v) => setT({ saleTaxRate: v })} />
             </>
           )}
         </>
diff --git a/src/lib/calculations.ts b/src/lib/calculations.ts
index 160a302..2ea96f3 100644
--- a/src/lib/calculations.ts
+++ b/src/lib/calculations.ts
@@ -2,6 +2,9 @@ import {
   AHV_COUPLE_CAP_FACTOR,
   AHV_FULL_CONTRIBUTION_YEARS,
   AHV_MAX_ANNUAL_SINGLE,
+  DEFAULT_CAPITAL_TAX_RATE,
+  DEFAULT_PK_CONVERSION_RATE,
+  DEFAULT_PROPERTY_GAINS_TAX_RATE,
 } from "@/lib/constants";
 import { num } from "@/lib/elements";
 import type { ElementCategory } from "@/lib/elements";
@@ -459,18 +462,18 @@ export function computePlan(plan: PlanInput): PlanComputed {
             const value = ec.endValue;
             const mode = td.payoutMode ?? "PENSION";
             if (mode === "CAPITAL") {
-              const net = Math.round(value * (1 - num(td.capitalTaxRate) / 100));
+              const net = Math.round(value * (1 - num(td.capitalTaxRate, DEFAULT_CAPITAL_TAX_RATE) / 100));
               outgoing += net;
               carry.value = 0;
               carry.pkPensionAnnual = 0;
             } else if (mode === "PENSION") {
-              carry.pkPensionAnnual = Math.round((value * num(td.conversionRate)) / 100);
+              carry.pkPensionAnnual = Math.round((value * num(td.conversionRate, DEFAULT_PK_CONVERSION_RATE)) / 100);
               carry.value = 0;
             } else {
               const capital = Math.min(value, Math.round(num(td.capitalAmount)));
-              const net = Math.round(capital * (1 - num(td.capitalTaxRate) / 100));
+              const net = Math.round(capital * (1 - num(td.capitalTaxRate, DEFAULT_CAPITAL_TAX_RATE) / 100));
               outgoing += net;
-              carry.pkPensionAnnual = Math.round(((value - capital) * num(td.conversionRate)) / 100);
+              carry.pkPensionAnnual = Math.round(((value - capital) * num(td.conversionRate, DEFAULT_PK_CONVERSION_RATE)) / 100);
               carry.value = 0;
             }
           } else {
@@ -482,7 +485,7 @@ export function computePlan(plan: PlanInput): PlanComputed {
         }
         case "PILLAR_3A": {
           if (ownerRetiresNext) {
-            const net = Math.round(ec.endValue * (1 - num(td.capitalTaxRate) / 100));
+            const net = Math.round(ec.endValue * (1 - num(td.capitalTaxRate, DEFAULT_CAPITAL_TAX_RATE) / 100));
             outgoing += net;
             carry.value = 0;
           } else {
@@ -506,7 +509,7 @@ export function computePlan(plan: PlanInput): PlanComputed {
             const purchase = Math.round(num(e.phaseValues[phase.id]?.purchasePrice));
             const salePrice = Math.round(num(td.salePrice));
             const gain = Math.max(0, salePrice - purchase);
-            const tax = gain * (num(td.saleTaxRate) / 100);
+            const tax = gain * (num(td.saleTaxRate, DEFAULT_PROPERTY_GAINS_TAX_RATE) / 100);
             outgoing += Math.round(salePrice - carry.mortgage - tax);
             carry.status = "SOLD";
           }
diff --git a/src/lib/constants.ts b/src/lib/constants.ts
index 4656b2d..a1c0726 100644
--- a/src/lib/constants.ts
+++ b/src/lib/constants.ts
@@ -13,6 +13,12 @@ export const AHV_COUPLE_CAP_FACTOR = 1.5;
 // Beitragsjahr (Ausfalljahr) wird die Rente um 1/44 gekuerzt.
 export const AHV_FULL_CONTRIBUTION_YEARS = 44;
 
-// Maximaler jaehrlicher Saeule-3a-Beitrag fuer PK-Versicherte (2026). Wird in
-// 100er-Schritten erfasst (nicht 1'000er wie andere Betraege).
+// Maximaler jaehrlicher Saeule-3a-Beitrag fuer PK-Versicherte (2026).
 export const PILLAR_3A_MAX_ANNUAL = 7258;
+
+// Default-Annahmen fuer Uebergangs-Ereignisse (pro Ereignis editierbar). Werden SOWOHL als
+// UI-Vorschlag als auch in der Berechnung als Fallback verwendet -- damit ein nicht
+// angetupfter Wert nicht faelschlich als 0 gerechnet wird.
+export const DEFAULT_PK_CONVERSION_RATE = 6; // % (jaehrliche Rente = Kapital x Satz)
+export const DEFAULT_CAPITAL_TAX_RATE = 8; // % Kapitalbezugssteuer (PK-/3a-Kapitalbezug)
+export const DEFAULT_PROPERTY_GAINS_TAX_RATE = 20; // % Grundstueckgewinnsteuer