{"uid":"cap__XK5k07bVGI-RxhnDHH8A","slug":"saylor-innovations-loan-payoff-calculator-with-extra-payments-83d0ddfc","name":"Saylor Innovations Loan Payoff Calculator with Extra Payments","description":"Loan payoff with extra payments - monthly payment, months and interest saved, new payoff length and totals versus the original schedule","url":"https://saylorinnovations.com/api/finance/loan-payoff?utm_source=zero.xyz","method":"GET","headers":{},"bodySchema":{"type":"object","$schema":"https://json-schema.org/draft/2020-12/schema","required":["input"],"properties":{"input":{"type":"object","required":["type","method"],"properties":{"type":{"type":"string","const":"http"},"method":{"enum":["GET"],"type":"string"},"queryParams":{"type":"object","required":["principal","apr","term_months"],"properties":{"apr":{"type":"string","description":"Annual rate in percent"},"principal":{"type":"string","description":"Loan amount"},"term_months":{"type":"string","description":"Loan term in months"},"extra_monthly":{"type":"string","description":"optional extra payment each month"}}}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string","const":"json"},"example":{"type":"object","required":["monthly_payment","baseline","with_extra"],"properties":{"source":{"type":"string","description":"Data source the values come from"},"baseline":{"type":"object","description":"Original schedule: months, total interest and total paid"},"principal":{"type":"number","description":"Starting principal amount"},"with_extra":{"type":"object","description":"With extra"},"apr_percent":{"type":"number","description":"Apr, as a percentage"},"term_months":{"type":"number","description":"Term months"},"months_saved":{"type":"number","description":"Months saved"},"interest_saved":{"type":"number","description":"Interest saved"},"monthly_payment":{"type":"number","description":"Monthly payment amount"},"payoff_years_with_extra":{"type":["number","null"],"description":"Payoff years with extra"}}}}}}},"responseSchema":null,"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.01","displayCostAsset":"USDC","priceDynamic":false,"priceHint":null,"priceStatus":"priced","priceSource":"probe","requiresHandshake":false,"reviewCount":0,"rating":{"score":"0.00","successRate":"0.00","reviews":0,"stars":null,"state":"unrated"},"availabilityStatus":"unknown","priceObserved":null,"sessionDeposit":null,"pricing":{"kind":"static","summary":"$0.01/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.01","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.01","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_dROV8QwsCmrtRs5C7YQS5","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.01","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Calculates the impact of making extra monthly payments on a loan — showing monthly payment, months and interest saved, new payoff length, and totals versus the original schedule","exampleAgentPrompt":"If I have a $250,000 mortgage at 6.5% APR over 360 months and I pay an extra $300 each month, how much interest will I save and how many months sooner will I pay it off?","exampleUseCases":[{"title":"Mortgage overpayment savings check","prompt":"I have a $350,000 home loan at 7% APR with 300 months left — if I throw an extra $500 at it each month, how much interest do I save and when will I actually be done paying it off?"},{"title":"Car loan early payoff analysis","prompt":"My car loan is $18,000 at 5.9% APR over 60 months. What happens to my payoff timeline and total interest if I pay an extra $150 per month?"},{"title":"Student loan repayment planning","prompt":"I owe $45,000 in student loans at 4.5% APR on a 120-month plan. How much would I save in interest if I added $200 extra to my payment every month, and how many months earlier would I be debt-free?"}],"resultDescription":"Returns the standard monthly payment, a baseline schedule showing total months, total interest and total paid under the original plan, and a with-extra breakdown showing reduced payoff length, total interest paid, total paid, months saved, interest saved, and years to payoff with the extra payment applied each month.","failureModes":["Missing required parameters (principal, apr, or term_months) returns an error","Non-numeric or negative values for principal, APR, or term cause validation errors","APR of 0% may produce division edge cases or unexpected output","Very large extra payments that exceed the loan balance may produce unexpected results","Invalid query parameter formatting (e.g. letters instead of numbers) returns a bad request error"],"whenToPreferThis":"Use this endpoint when you need a quick, accurate computation of the financial impact of extra loan payments — covering savings in interest and time — compared to the original amortization schedule. It is ideal for personal finance agents, mortgage advisors, or budgeting tools that want to show users a clear before/after comparison without building their own amortization engine. Prefer this over a full amortization table endpoint when the user only needs summary savings figures rather than a month-by-month breakdown.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-27T19:22:18.450Z","isFirstParty":false,"canonicalSlug":"saylor-innovations-loan-payoff-calculator-with-extra-payments-83d0ddfc"}