{"ok":true,"tool":"Loan Payoff Calculator","operation":"calculateLoanPayoff","description":"Compare a loan's standard amortization with an accelerated schedule that adds an extra monthly payment, returning months and interest saved.","method":"POST","endpoint":"/api/loan-payoff-calculator","webUrl":"https://ultraquick.tools/tools/loan-payoff-calculator","parameters":{"type":"object","properties":{"principal":{"type":"number","description":"Loan principal (amount borrowed)."},"annualRate":{"type":"number","description":"Annual interest rate as a percentage (e.g. 5 for 5%)."},"years":{"type":"number","description":"Loan term in years. Used to derive the scheduled payment if monthlyPayment is not given."},"monthlyPayment":{"type":"number","description":"Scheduled monthly payment. Overrides the years-based calculation when provided."},"extraPayment":{"type":"number","description":"Extra amount paid toward principal each month (default 0)."}},"required":["principal","annualRate"]},"response":{"type":"object","properties":{"scheduledPayment":{"type":"number","description":"The monthly payment used (derived from years or provided)."},"standard":{"type":"object","description":"Standard schedule: months, totalInterest, totalPaid, payoffPossible."},"accelerated":{"type":"object","description":"Accelerated schedule with extra payment: months, totalInterest, totalPaid, payoffPossible."},"monthsSaved":{"type":"number","description":"Months shaved off the loan by the extra payment."},"interestSaved":{"type":"number","description":"Interest saved over the life of the loan."}}},"example":{"request":{"principal":200000,"annualRate":5,"years":30,"extraPayment":200},"response_shape":{"type":"object","properties":{"scheduledPayment":{"type":"number","description":"The monthly payment used (derived from years or provided)."},"standard":{"type":"object","description":"Standard schedule: months, totalInterest, totalPaid, payoffPossible."},"accelerated":{"type":"object","description":"Accelerated schedule with extra payment: months, totalInterest, totalPaid, payoffPossible."},"monthsSaved":{"type":"number","description":"Months shaved off the loan by the extra payment."},"interestSaved":{"type":"number","description":"Interest saved over the life of the loan."}}}},"howToCall":"POST a JSON body to https://ultraquick.tools/api/loan-payoff-calculator. Returns {\"ok\":true,\"result\":{...}} on success or {\"ok\":false,\"error\":\"...\"} on failure. No auth, CORS-enabled.","parametersSummary":"  principal (number, required) — Loan principal (amount borrowed).\n  annualRate (number, required) — Annual interest rate as a percentage (e.g. 5 for 5%).\n  years (number, optional) — Loan term in years. Used to derive the scheduled payment if monthlyPayment is not given.\n  monthlyPayment (number, optional) — Scheduled monthly payment. Overrides the years-based calculation when provided.\n  extraPayment (number, optional) — Extra amount paid toward principal each month (default 0).","curlExample":"curl -X POST https://ultraquick.tools/api/loan-payoff-calculator -H \"Content-Type: application/json\" -d '{\"principal\":200000,\"annualRate\":5,\"years\":30,\"extraPayment\":200}'"}