{"uid":"cap_HLwbFehM3qUS6apgHWpIo","slug":"future-value-calculator-finance-openverbs-com-c2a1bcc1","name":"Future Value Calculator (finance.openverbs.com)","description":"Future value of a present sum and/or a level annuity, given a per-period rate and number of periods. Set dueAtBeginning=true for an annuity-due (payments at the start of each period).","url":"https://finance.openverbs.com/v1/future-value","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":["ratePercent","periods"],"properties":{"payment":{"type":"number","description":"Level payment per period (annuity). Default 0."},"periods":{"type":"integer","maximum":100000,"minimum":0,"description":"Number of periods."},"ratePercent":{"type":"number","maximum":1000,"minimum":-99,"description":"Interest rate per period, as a percentage."},"presentValue":{"type":"number","description":"Present lump sum. Default 0."},"dueAtBeginning":{"type":"boolean","description":"Annuity-due (payments at period start). Default false."}},"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_NR74tf4-LGipOgEpuFhmh","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 future value of a present lump sum and/or a level periodic payment (annuity), given a per-period interest rate and number of periods, with support for annuity-due timing.","exampleAgentPrompt":"If I invest $5,000 today and add $200 every month for 15 years at a 6% annual rate (so 0.5% per period), what will my investment be worth at the end?","exampleUseCases":[{"title":"Retirement savings projection","prompt":"I'm starting a retirement account with $10,000 today and plan to contribute $400 per month for 30 years. If I earn 7% per year (so about 0.583% per period), how much will I have at retirement?"},{"title":"Lump-sum college fund growth","prompt":"I'm putting $25,000 into a 529 college fund today and won't add anything else. At a 4% annual interest rate compounded yearly for 18 years, what will it grow to?"},{"title":"Annuity-due future value comparison","prompt":"My client makes $1,000 contributions at the start of each month for 24 months at 0.5% per period. What's the future value of those payments using annuity-due timing?"}],"resultDescription":"A computed future value figure representing how much a present sum and/or a series of level periodic payments will be worth after a given number of compounding periods at the specified per-period interest rate. The response reflects ordinary annuity (end-of-period payments) or annuity-due (beginning-of-period payments) depending on the dueAtBeginning flag.","failureModes":["Missing required fields (ratePercent or periods) returns a validation error","periods exceeding 100,000 or ratePercent outside -99 to 1000 range returns a 400 bad request","Negative interest rates near -99% may produce near-zero or unexpected results","Non-integer periods value is rejected by the schema","Incorrect bodyType (not json/form-data/text) causes a request format error","Payment/presentValue not provided defaults to 0, which may produce a trivial result if the caller forgets to include them"],"whenToPreferThis":"Choose this endpoint when you need a standard time-value-of-money future value calculation for a lump sum, a level annuity, or a combination of both. It handles both ordinary annuity and annuity-due conventions via the dueAtBeginning flag. Prefer it over general compound interest endpoints when periodic payments are involved, and over NPV/IRR endpoints when you are projecting forward rather than discounting cash flows.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-15T00:42:15.176Z","isFirstParty":false}