Annuity Payout Calculator

Before you calculate

Use this calculator when you want to test a level withdrawal-style payout from a balance before looking at a real annuity contract, pension option, provider quote, tax treatment, or adviser recommendation. Use the Annuity Calculator for accumulation before payout, Retirement for a wider savings and withdrawal estimate, 401K for employer-plan scenarios, and RMD for US required-minimum-distribution estimates.

Formula summary

The app maps payout frequency to periods per year: annually 1, semiannually 2, quarterly 4, monthly 12, semimonthly 24, and biweekly 26. It converts the annual rate to an effective payout-period rate with (1 + interestRate / 100)^(1 / periodsPerYear) - 1. Fixed-length mode uses PMT = P * i / (1 - (1 + i)^-n), with a zero-rate fallback of P / n. Fixed-payment mode solves n = -ln(1 - P * i / payment) / ln(1 + i), with zero-rate and non-depleting branches when the entered payment cannot create a finite depletion period.

Worked example

Example: default fixed length and fixed payment

With the default fixed-length inputs, $500,000 starting principal, a 6 percent annual interest or return assumption, 10 years, and monthly frequency produce a solved monthly payout of $5,511.20. The model uses 120 payout periods, total payments of $661,344.16, total interest or return of $161,344.16, an effective period rate displayed as 0.49 percent, and a simplified $0 ending balance. In fixed-payment mode with the same principal, rate, and monthly frequency, a $5,000 payment lasts about 11.45 years, or 137.36 periods, with total payments of $686,817.82 and total interest or return of $186,817.82.

The examples show how mode, payout frequency, rate, and payout amount or years change the math. They do not quote an insurer, compare pension products, calculate tax, model lifetime income, or recommend a payout choice.

Assumptions

• The starting principal, annual interest or return rate, payout frequency, payout years, and payout amount stay fixed for the estimate. The calculator does not pull live annuity rates, provider quotes, insurer terms, pension options, tax tables, product fees, surrender charges, inflation adjustments, mortality credits, or adviser recommendations.
• Fixed-length mode uses Years to payout and solves Payout amount. Fixed-payment mode uses Payout amount and solves Payout years; both fields can be present in the form, but only the mode-relevant field drives the main solve.
• Scoped independent comparator checks pass 4 of 4 scoped fixtures for overlapping payout amount, total payments, total interest or return, and payout-year behavior. Investor.gov and SEC sources are needed before copy discusses real annuity contracts, risks, fees, guarantees, or registered products; IRS Publication 575 is needed before US pension or annuity tax claims; FCA, MoneyHelper, provider, or adviser sources are needed before UK annuity-shopping or regulated-product claims. Results are educational estimates, not financial, tax, legal, pension, insurance, investment, regulated-product, or personalised advice.

Common mistakes to avoid

• Using fixed-length and then expecting the entered Payout amount to control the result. In fixed-length mode the calculator solves that amount from principal, rate, frequency, and years.
• Using fixed-payment and then reading the Years to payout field as the controlling term. In fixed-payment mode the calculator solves the duration from the entered payment amount and may report fractional periods.
• Treating a non-depleting branch, a zero-rate branch, or the displayed $0 ending balance as a guaranteed annuity income stream, provider statement, tax answer, pension recommendation, or product illustration.

Methodology and sources

This calculator is an original implementation based on documented formulas, app-specific assumptions, deterministic fixtures, edge cases, rounding policy tests, and internal validation. It is not copied from a single source.

Outputs are checked with deterministic fixtures, edge cases, rounding policy tests, and internal independent comparator checks where overlapping outputs are available. The result remains an educational estimate, not a quote, approval, tax answer, or personalised advice.

Formula version 2026.05.22-generic-annuity-payout. The version marks the calculation logic and validation fixture set used for this estimate.

• Investor.gov and SEC investor education should be used when copy discusses annuity contracts, variable annuities, payout options, withdrawals, surrender charges, fees, risks, insurer guarantees, registered products, or professional checks.
• IRS Publication 575 should be used when copy discusses US pension and annuity income tax treatment, periodic annuity payments, early withdrawals, the Simplified Method, the General Rule, or pension-plan distributions.
• FCA and MoneyHelper sources should be used when copy discusses UK pension annuities, guaranteed retirement income, shopping around, provider comparisons, adviser or broker access, pension pots, fixed-term annuities, lifetime annuities, or regulated product context.

Estimate only

The result is educational and is not financial, tax, legal, lending, investment, or regulated advice. Real provider terms, fees, rates, taxes, and personal circumstances can change the final answer.

Formula and help: read the full annuity payout calculator methodology notes.

Related reading

• Retirement planning with simple estimates
• How Calcs.finance validates calculator formulas
• Estimate limitations and not-advice disclaimer

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