{"uid":"cap_ei27pMIzSBo32ftqYHfYr","slug":"simple-and-compound-interest-calculator-ea8f8e87","name":"Simple and Compound Interest Calculator","description":"Grow a principal by simple or compound interest over a number of years. Compound interest uses compoundsPerYear compounding periods (default 12, monthly).","url":"https://finance.openverbs.com/v1/interest","method":"POST","headers":{},"bodySchema":{"type":"object","$schema":"https://json-schema.org/draft/2020-12/schema","required":["input"],"properties":{"input":{"type":"object","required":["type","method","bodyType","body"],"properties":{"body":{"type":"object","required":["principal","annualRatePercent","years"],"properties":{"years":{"type":"number","maximum":1000,"minimum":0,"description":"Number of years."},"method":{"enum":["simple","compound"],"type":"string","description":"Interest method. Default compound."},"principal":{"type":"number","maximum":1000000000000000,"minimum":0,"description":"Starting principal."},"compoundsPerYear":{"type":"integer","maximum":365,"minimum":1,"description":"Compounding periods per year (compound only). Default 12."},"annualRatePercent":{"type":"number","maximum":1000,"minimum":0,"description":"Annual interest rate as a percentage."}},"additionalProperties":false},"type":{"type":"string","const":"http"},"method":{"enum":["POST"],"type":"string"},"bodyType":{"enum":["json","form-data","text"],"type":"string"}},"additionalProperties":false}}},"responseSchema":null,"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.004","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":"$0.004/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.004","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.004","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_5ZBMUabJhYHgzU6A5MPvH","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.004","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Calculates the final amount after growing a principal by simple or compound interest over a specified number of years, with configurable compounding frequency.","exampleAgentPrompt":"If I invest $25,000 at an annual rate of 6.5% compounded monthly for 10 years, how much will it grow to?","exampleUseCases":[{"title":"Savings account growth projection","prompt":"I have $15,000 in a savings account earning 4.2% annual interest compounded monthly. How much will I have after 5 years?"},{"title":"Simple interest loan cost estimate","prompt":"Calculate the simple interest on a $50,000 loan at 7% per year over 3 years — I want to know the total amount I'd owe at the end."},{"title":"Retirement nest egg compounding","prompt":"If I put $100,000 into an account earning 8% per year compounded quarterly, what will it be worth in 30 years?"}],"resultDescription":"Returns the grown principal amount after applying simple or compound interest over the specified period, reflecting the starting principal, annual rate, number of years, and compounding frequency.","failureModes":["Missing required fields (principal, annualRatePercent, years) returns a validation error","Years or rate exceeding maximum bounds (1000 years, 1000% rate) returns a range error","Invalid method enum value (not 'simple' or 'compound') returns a schema validation error","compoundsPerYear outside 1–365 range returns a validation error","Non-numeric input for numeric fields returns a type error"],"whenToPreferThis":"Use this endpoint when you need a straightforward interest growth calculation given a fixed annual rate, principal, and time period — either simple or compound. Prefer this over future value or NPV endpoints when you are not dealing with recurring cash flows or annuities, just a lump sum growing at a fixed rate. Ideal for savings projections, loan interest estimates, and basic investment modeling.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-15T00:31:40.058Z","isFirstParty":false}