diff --git a/app/api/households/[id]/debt-payoff/route.ts b/app/api/households/[id]/debt-payoff/route.ts
new file mode 100644
index 0000000..f79b502
--- /dev/null
+++ b/app/api/households/[id]/debt-payoff/route.ts
@@ -0,0 +1,9 @@
+import { NextRequest } from "next/server";
+import { proxyRequest } from "@/lib/backend";
+
+export async function POST(
+  req: NextRequest,
+  { params }: { params: { id: string } }
+) {
+  return proxyRequest(req, `households/${params.id}/debt-payoff`);
+}
diff --git a/app/settings/households/page.tsx b/app/settings/households/page.tsx
index 6b2a4c4..66c316a 100644
--- a/app/settings/households/page.tsx
+++ b/app/settings/households/page.tsx
@@ -171,6 +171,40 @@ type MoneyDatePromptResponse = {
   prompts: MoneyDatePrompt[];
 };
 
+type DebtPayoffResult = {
+  strategy: "avalanche" | "snowball" | "custom";
+  monthlyExtraPayment: number;
+  monthlyPayment: number;
+  totalStartingBalance: number;
+  totalInterestPaid: number;
+  payoffMonths: number;
+  payoffYears: number;
+  contributionSplit: {
+    splitMode: "equal" | "income_weighted" | "custom";
+    minePercent: number;
+    yoursPercent: number;
+    mineAmount: number;
+    yoursAmount: number;
+    rationale: string;
+  };
+  orderedDebts: Array<{
+    name: string;
+    startingBalance: number;
+    annualPercentageRate: number;
+    minimumPayment: number;
+    payoffOrder: number;
+  }>;
+  timeline: Array<{
+    month: number;
+    targetDebt: string;
+    totalRemainingBalance: number;
+    interestPaid: number;
+    principalPaid: number;
+    paidOffDebts: string[];
+  }>;
+  recommendations: string[];
+};
+
 const money = new Intl.NumberFormat("en-US", {
   style: "currency",
   currency: "USD",
@@ -228,6 +262,20 @@ export default function HouseholdSettingsPage() {
   });
   const [fairSplitResult, setFairSplitResult] = useState<FairSplitResult | null>(null);
   const [fairSplitStatus, setFairSplitStatus] = useState("");
+  const [debtDraft, setDebtDraft] = useState({
+    strategy: "avalanche" as "avalanche" | "snowball" | "custom",
+    monthlyExtraPayment: "300",
+    splitMode: "income_weighted" as "equal" | "income_weighted" | "custom",
+    mineMonthlyIncome: "",
+    yoursMonthlyIncome: "",
+    customMinePercent: "50",
+    debts: [
+      { name: "Credit card", balance: "", annualPercentageRate: "", minimumPayment: "", priority: "1" },
+      { name: "Personal loan", balance: "", annualPercentageRate: "", minimumPayment: "", priority: "2" },
+    ],
+  });
+  const [debtPayoffResult, setDebtPayoffResult] = useState<DebtPayoffResult | null>(null);
+  const [debtPayoffStatus, setDebtPayoffStatus] = useState("");
   const [privacyStatus, setPrivacyStatus] = useState("");
   const [moneyDatePrompts, setMoneyDatePrompts] = useState<MoneyDatePromptResponse | null>(null);
   const [moneyDateStatus, setMoneyDateStatus] = useState("");
@@ -451,6 +499,62 @@ export default function HouseholdSettingsPage() {
     setFairSplitStatus("");
   };
 
+  const updateDebtDraft = (index: number, field: "name" | "balance" | "annualPercentageRate" | "minimumPayment" | "priority", value: string) => {
+    setDebtDraft((prev) => ({
+      ...prev,
+      debts: prev.debts.map((debt, i) => i === index ? { ...debt, [field]: value } : debt),
+    }));
+  };
+
+  const addDebtDraftRow = () => {
+    setDebtDraft((prev) => ({
+      ...prev,
+      debts: [
+        ...prev.debts,
+        { name: `Debt ${prev.debts.length + 1}`, balance: "", annualPercentageRate: "", minimumPayment: "", priority: String(prev.debts.length + 1) },
+      ],
+    }));
+  };
+
+  const calculateDebtPayoff = async (event: FormEvent) => {
+    event.preventDefault();
+    if (!selectedId) return;
+    const debts = debtDraft.debts
+      .filter((debt) => debt.name.trim() && debt.balance && debt.minimumPayment)
+      .map((debt) => ({
+        name: debt.name,
+        balance: Number.parseFloat(debt.balance),
+        annualPercentageRate: Number.parseFloat(debt.annualPercentageRate || "0"),
+        minimumPayment: Number.parseFloat(debt.minimumPayment),
+        priority: Number.parseInt(debt.priority || "0", 10),
+      }));
+    if (!debts.length) {
+      setDebtPayoffStatus("Add at least one debt with balance and minimum payment.");
+      return;
+    }
+
+    setDebtPayoffStatus("Calculating debt payoff plan...");
+    const res = await apiFetch<DebtPayoffResult>(`/api/households/${selectedId}/debt-payoff`, {
+      method: "POST",
+      body: JSON.stringify({
+        strategy: debtDraft.strategy,
+        monthlyExtraPayment: Number.parseFloat(debtDraft.monthlyExtraPayment || "0"),
+        splitMode: debtDraft.splitMode,
+        mineMonthlyIncome: Number.parseFloat(debtDraft.mineMonthlyIncome || "0"),
+        yoursMonthlyIncome: Number.parseFloat(debtDraft.yoursMonthlyIncome || "0"),
+        customMinePercent: debtDraft.splitMode === "custom" ? Number.parseFloat(debtDraft.customMinePercent) : undefined,
+        debts,
+      }),
+    });
+    if (res.error) {
+      setDebtPayoffResult(null);
+      setDebtPayoffStatus(res.error.message ?? "Unable to calculate debt payoff plan.");
+      return;
+    }
+    setDebtPayoffResult(res.data ?? null);
+    setDebtPayoffStatus("");
+  };
+
   const updateMemberAccess = async (member: HouseholdMember, payload: { role?: string; status?: string }) => {
     if (!selectedId) return;
     const res = await apiFetch<HouseholdMember>(`/api/households/${selectedId}/members/${member.id}`, {
@@ -794,6 +898,145 @@ export default function HouseholdSettingsPage() {
               </div>
             </div>
 
+            <div className="glass-panel rounded-2xl p-6 shadow-sm">
+              <div className="grid gap-6 xl:grid-cols-[0.9fr_1.1fr]">
+                <div>
+                  <p className="text-xs font-semibold uppercase tracking-wider text-muted-foreground">Debt payoff teamwork</p>
+                  <h2 className="mt-2 text-xl font-bold text-foreground">Plan a shared payoff order and contribution split</h2>
+                  <p className="mt-2 text-sm text-muted-foreground">
+                    Compare avalanche, snowball, or custom priority and agree how much each partner contributes monthly.
+                  </p>
+                  {debtPayoffResult ? (
+                    <div className="mt-5 grid gap-3 sm:grid-cols-2">
+                      <div className="rounded-xl border border-border bg-background/40 p-4">
+                        <p className="text-xs font-semibold uppercase tracking-wider text-muted-foreground">Payoff time</p>
+                        <p className="mt-2 text-2xl font-bold text-foreground">{debtPayoffResult.payoffMonths} months</p>
+                        <p className="text-sm text-muted-foreground">{debtPayoffResult.payoffYears} years</p>
+                      </div>
+                      <div className="rounded-xl border border-border bg-background/40 p-4">
+                        <p className="text-xs font-semibold uppercase tracking-wider text-muted-foreground">Interest</p>
+                        <p className="mt-2 text-2xl font-bold text-foreground">{formatMoney(debtPayoffResult.totalInterestPaid)}</p>
+                        <p className="text-sm text-muted-foreground">{formatMoney(debtPayoffResult.monthlyPayment)} monthly plan</p>
+                      </div>
+                      <div className="rounded-xl border border-border bg-background/40 p-4">
+                        <p className="text-xs font-semibold uppercase tracking-wider text-muted-foreground">Mine</p>
+                        <p className="mt-2 text-2xl font-bold text-foreground">{formatMoney(debtPayoffResult.contributionSplit.mineAmount)}</p>
+                        <p className="text-sm text-muted-foreground">{debtPayoffResult.contributionSplit.minePercent}% monthly share</p>
+                      </div>
+                      <div className="rounded-xl border border-border bg-background/40 p-4">
+                        <p className="text-xs font-semibold uppercase tracking-wider text-muted-foreground">Yours</p>
+                        <p className="mt-2 text-2xl font-bold text-foreground">{formatMoney(debtPayoffResult.contributionSplit.yoursAmount)}</p>
+                        <p className="text-sm text-muted-foreground">{debtPayoffResult.contributionSplit.yoursPercent}% monthly share</p>
+                      </div>
+                      <div className="sm:col-span-2 rounded-xl border border-border bg-background/40 p-4">
+                        <p className="text-sm font-semibold text-foreground">Payoff order</p>
+                        <div className="mt-3 space-y-2">
+                          {debtPayoffResult.orderedDebts.map((debt) => (
+                            <div key={`${debt.payoffOrder}-${debt.name}`} className="flex items-center justify-between gap-3 text-sm">
+                              <span className="text-foreground">{debt.payoffOrder}. {debt.name}</span>
+                              <span className="text-muted-foreground">{debt.annualPercentageRate}% APR · {formatMoney(debt.startingBalance)}</span>
+                            </div>
+                          ))}
+                        </div>
+                      </div>
+                    </div>
+                  ) : null}
+                </div>
+                <form onSubmit={calculateDebtPayoff} className="space-y-4">
+                  <div className="grid gap-3 md:grid-cols-3">
+                    <select
+                      value={debtDraft.strategy}
+                      onChange={(event) => setDebtDraft((prev) => ({ ...prev, strategy: event.target.value as "avalanche" | "snowball" | "custom" }))}
+                      className={inputClass}
+                    >
+                      <option value="avalanche">Avalanche</option>
+                      <option value="snowball">Snowball</option>
+                      <option value="custom">Custom order</option>
+                    </select>
+                    <input
+                      type="number"
+                      min="0"
+                      step="0.01"
+                      value={debtDraft.monthlyExtraPayment}
+                      onChange={(event) => setDebtDraft((prev) => ({ ...prev, monthlyExtraPayment: event.target.value }))}
+                      placeholder="Extra monthly payment"
+                      className={inputClass}
+                    />
+                    <select
+                      value={debtDraft.splitMode}
+                      onChange={(event) => setDebtDraft((prev) => ({ ...prev, splitMode: event.target.value as "equal" | "income_weighted" | "custom" }))}
+                      className={inputClass}
+                    >
+                      <option value="income_weighted">Income-weighted</option>
+                      <option value="equal">Equal 50/50</option>
+                      <option value="custom">Custom percent</option>
+                    </select>
+                    <input
+                      type="number"
+                      min="0"
+                      step="0.01"
+                      value={debtDraft.mineMonthlyIncome}
+                      onChange={(event) => setDebtDraft((prev) => ({ ...prev, mineMonthlyIncome: event.target.value }))}
+                      placeholder="Mine monthly income"
+                      className={inputClass}
+                    />
+                    <input
+                      type="number"
+                      min="0"
+                      step="0.01"
+                      value={debtDraft.yoursMonthlyIncome}
+                      onChange={(event) => setDebtDraft((prev) => ({ ...prev, yoursMonthlyIncome: event.target.value }))}
+                      placeholder="Yours monthly income"
+                      className={inputClass}
+                    />
+                    {debtDraft.splitMode === "custom" ? (
+                      <input
+                        type="number"
+                        min="0"
+                        max="100"
+                        step="0.01"
+                        value={debtDraft.customMinePercent}
+                        onChange={(event) => setDebtDraft((prev) => ({ ...prev, customMinePercent: event.target.value }))}
+                        placeholder="Mine percent"
+                        className={inputClass}
+                      />
+                    ) : null}
+                  </div>
+
+                  <div className="space-y-2">
+                    {debtDraft.debts.map((debt, index) => (
+                      <div key={index} className="grid gap-2 md:grid-cols-[1.2fr_1fr_1fr_1fr_80px]">
+                        <input value={debt.name} onChange={(event) => updateDebtDraft(index, "name", event.target.value)} placeholder="Debt name" className={inputClass} />
+                        <input type="number" min="0" step="0.01" value={debt.balance} onChange={(event) => updateDebtDraft(index, "balance", event.target.value)} placeholder="Balance" className={inputClass} />
+                        <input type="number" min="0" step="0.01" value={debt.annualPercentageRate} onChange={(event) => updateDebtDraft(index, "annualPercentageRate", event.target.value)} placeholder="APR %" className={inputClass} />
+                        <input type="number" min="0" step="0.01" value={debt.minimumPayment} onChange={(event) => updateDebtDraft(index, "minimumPayment", event.target.value)} placeholder="Minimum" className={inputClass} />
+                        <input type="number" min="1" step="1" value={debt.priority} onChange={(event) => updateDebtDraft(index, "priority", event.target.value)} placeholder="Order" className={inputClass} />
+                      </div>
+                    ))}
+                  </div>
+                  <div className="flex flex-col gap-2 sm:flex-row">
+                    <button type="button" onClick={addDebtDraftRow} className="rounded-lg border border-border px-4 py-2 text-sm font-semibold text-foreground hover:bg-secondary">
+                      Add debt
+                    </button>
+                    <button type="submit" className="rounded-lg bg-primary px-4 py-2 text-sm font-bold text-primary-foreground hover:bg-primary/90">
+                      Calculate payoff
+                    </button>
+                  </div>
+                  {debtPayoffStatus ? <p className="text-sm text-muted-foreground">{debtPayoffStatus}</p> : null}
+                  {debtPayoffResult?.recommendations.length ? (
+                    <div className="rounded-xl border border-border bg-background/40 p-4">
+                      <p className="text-sm font-semibold text-foreground">Team next steps</p>
+                      <div className="mt-2 space-y-1">
+                        {debtPayoffResult.recommendations.map((recommendation) => (
+                          <p key={recommendation} className="text-sm text-muted-foreground">{recommendation}</p>
+                        ))}
+                      </div>
+                    </div>
+                  ) : null}
+                </form>
+              </div>
+            </div>
+
             <div className="grid gap-6 xl:grid-cols-[0.9fr_1.1fr]">
               <div className="glass-panel rounded-2xl p-6 shadow-sm">
                 <div className="flex items-center justify-between gap-3">