{"uid":"cap_Wa6nUKJOktTh5RDAFZ_mO","slug":"saylor-innovations-apr-calculator-41bc8bf3","name":"Saylor Innovations APR Calculator","description":"Solve the true APR and effective annual rate of a loan from amount, level payment, number of payments and upfront fees, with total cost of credit.","url":"https://saylorinnovations.com/api/finance/apr-from-payment?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":["loan_amount","payment","months"],"properties":{"months":{"type":"string","description":"number of payments"},"payment":{"type":"string","description":"level monthly payment"},"loan_amount":{"type":"string","description":"amount borrowed"},"upfront_fees":{"type":"string","description":"optional fees deducted from the proceeds"}}}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string","const":"json"},"example":{"type":"object","required":["apr_percent","total_cost_of_credit"],"properties":{"note":{"type":"string","description":"Plain-language caveat about how to read and use the result"},"months":{"type":"number","description":"Number of payments"},"source":{"type":"string","description":"Where the data or formula comes from"},"payment":{"type":"number","description":"Level monthly payment"},"total_paid":{"type":"number","description":"Payment times months"},"apr_percent":{"type":"number","description":"Monthly rate times twelve, in percent"},"loan_amount":{"type":"number","description":"Amount borrowed"},"upfront_fees":{"type":"number","description":"Fees taken from the proceeds"},"amount_received":{"type":"number","description":"Loan amount minus upfront fees"},"monthly_rate_percent":{"type":"number","description":"Solved monthly interest rate"},"total_cost_of_credit":{"type":"number","description":"Total paid minus amount received"},"cost_per_100_borrowed":{"type":"number","description":"Cost of credit per 100 received"},"effective_annual_rate_percent":{"type":"number","description":"Annual rate with monthly compounding"}}}}}}},"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_by73LNSihOc_GVIGSa4KB","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":"Computes the true APR, effective annual rate, and total cost of credit for a loan given amount, payment, term, and upfront fees","exampleAgentPrompt":"What's the true APR and total cost of credit on a $10,000 loan where I pay $320 a month for 36 months and there's a $250 origination fee taken upfront?","exampleUseCases":[{"title":"Compare true cost of two loan offers","prompt":"I have two personal loan offers — one is $15,000 at $450/month for 36 months with no fees, the other is $15,000 at $420/month for 36 months but with a $500 origination fee. Can you calculate the true APR and total cost of credit for the second one so I can compare them properly?"},{"title":"Verify advertised APR on auto loan","prompt":"The dealership says my car loan APR is 6.9%, but I'm borrowing $22,000, paying $675 a month for 36 months, and there's a $300 documentation fee deducted from the proceeds. Can you solve for the actual APR to see if they're quoting it correctly?"},{"title":"Estimate real cost of payday-style installment loan","prompt":"I'm looking at a short-term loan — I'd receive $500, make 6 monthly payments of $110, and there's a $50 fee taken off the top. What's the true APR and cost of credit per $100 borrowed on that?"}],"resultDescription":"Returns the solved monthly interest rate, nominal APR (monthly rate × 12), effective annual rate (with monthly compounding), total amount paid, total cost of credit (total paid minus amount received after fees), cost per $100 borrowed, and a plain-language note on interpreting the result.","failureModes":["Missing required query parameters (loan_amount, payment, months) returns an error","No mathematical solution exists if payment is too low to cover interest — solver may return an error or zero rate","Very large or very small values may cause numerical solver instability","Non-numeric string inputs for numeric fields will cause a parse error","Upfront fees exceeding loan amount produce a zero or negative amount_received edge case"],"whenToPreferThis":"Use this endpoint when you need to compute the true borrowing cost of a fixed-payment loan, especially when upfront fees distort the nominal rate. It is ideal for comparing loan offers on an apples-to-apples APR basis, verifying lender-quoted rates, or surfacing the total cost of credit. Prefer this over generic financial calculators when you need both APR and EAR with fee-adjusted proceeds in a single call.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-10-30T07:13:04.393Z","isFirstParty":false,"canonicalSlug":"saylor-innovations-apr-calculator-41bc8bf3"}