Annuity Payout Calculator

At its core, this calculator solves for the periodic payment amount using the present value of an annuity formula. You provide three inputs — your starting balance (present value), an assumed annual interest rate, and the number of months or years you want the money to last — and the calculator returns the fixed monthly payout that will draw the account down to exactly zero by the end of that period. This is distinct from simply dividing your balance by the number of months, because the account continues earning interest on its remaining balance throughout the drawdown phase, allowing each payment to be larger than a simple division would suggest.

The interest rate assumption is the single most powerful lever in the calculation. A higher credited rate — whether it reflects an annuity contract's guaranteed rate, a portfolio's expected return, or a high-yield savings account's APY — meaningfully increases the sustainable monthly payout. For example, a $500,000 balance paid out over 20 years at 0% interest yields roughly $2,083 per month, while the same balance at a 5% annual rate supports approximately $3,300 per month. This gap illustrates why retirees who hold assets in low-yield instruments may significantly underestimate what a properly invested or annuitized balance could actually deliver as retirement income.

The payout period you choose reflects a critical planning judgment: how long do you need the income to last? For a fixed-term annuity or a pension bridge strategy, you might target a specific number of years. For lifetime income planning, actuarial life expectancy tables are typically used — in the US, a 65-year-old should generally plan for at least 25–30 years of income to avoid longevity risk. Choosing too short a period will deplete your funds prematurely, while choosing an overly conservative period reduces your monthly income more than necessary. Running the calculator across several time horizons simultaneously is the best way to bracket a realistic withdrawal plan.

A common mistake is ignoring inflation's erosion of purchasing power over time. This calculator produces a fixed nominal payout — $3,000 per month today will feel like considerably less in 20 years at even modest inflation. Sophisticated users often subtract an assumed inflation rate (e.g., 2–3%) from the nominal interest rate to get a 'real' rate, then run the calculation on that adjusted figure to model inflation-adjusted spending power. Additionally, taxes on withdrawals — which vary based on whether funds originate from a pre-tax IRA, Roth account, or insurance annuity contract — are not included in this tool and should be factored into your net income planning separately.