{"uid":"cap_8PPzU-iaf-x5nIPLT9eK5","slug":"roth-conversion-tax-cost-calculator-fca02c2a","name":"Roth Conversion Tax Cost Calculator","description":"Federal tax cost of a Roth conversion in one year: the extra income tax from stacking the converted amount on top of your other taxable income, with the marginal rate before and after.","url":"https://x402toll.com/v1/retirement/roth-conversion","method":"POST","headers":{},"bodySchema":{"type":"object","properties":{"filingStatus":{"enum":["single","mfj"],"type":"string","default":"single"},"conversionAmount":{"type":"number","maximum":1000000000,"minimum":0},"otherTaxableIncome":{"type":"number","default":0}}},"responseSchema":null,"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.1","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":"$0.1/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.1","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.1","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm__voYdVnqEt3iLBaWQwVJ9","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.1","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Calculates the incremental federal income tax cost of converting a given amount to a Roth IRA in a single year, showing marginal rates before and after the conversion.","exampleAgentPrompt":"I'm thinking of converting $60,000 from my traditional IRA to a Roth this year — I'm single and my other taxable income is about $85,000. How much extra federal tax will that Roth conversion cost me, and what marginal rates am I at before and after?","exampleUseCases":null,"resultDescription":"Returns the incremental federal income tax cost of the Roth conversion, the marginal tax rate bracket the filer was in before the conversion, and the marginal tax rate bracket pushed into after stacking the conversion amount on top of other taxable income.","failureModes":["conversionAmount or otherTaxableIncome exceeds maximum allowed value (1,000,000,000) — returns validation error","Invalid or missing filingStatus enum value — returns schema validation error","Non-numeric values for conversionAmount or otherTaxableIncome — returns 400 bad request","Payment not received or insufficient USDC balance — returns 402 Payment Required"],"whenToPreferThis":"Use this endpoint when you need to compute the precise incremental federal income tax cost of a Roth IRA conversion for a single tax year, broken down by pre- and post-conversion marginal rates. Prefer this over generic tax calculators when the user's specific question is about the marginal tax impact of stacking a Roth conversion on top of existing taxable income, especially for planning 'what-if' scenarios.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-14T19:01:35.811Z","isFirstParty":false}