Annuity Calculator

An annuity is a series of equal payments made at regular intervals. Common examples include monthly retirement payouts, mortgage payments, and bond coupons. This calculator handles two views: how much a lump sum will grow with ongoing contributions (future mode), and what periodic income a lump sum can sustain over a set number of years (income mode).

Switch to income mode, enter your starting balance, annual interest rate, and how many years you want payments to last. The calculator solves for the equal periodic payment that draws the balance to zero, using the same loan-amortization formula. For example, a $200,000 principal at 5% annual rate over 20 years with monthly payments yields roughly $1,320 per month.

Income mode starts with a lump sum and calculates how much you can withdraw each period until the balance reaches zero. Future mode starts with a lump sum plus a recurring contribution and projects the ending balance after a set number of years. Use income mode for retirement drawdown planning and future mode for savings accumulation.

No. All figures are pre-tax. Annuity income and investment growth may be taxed as ordinary income or capital gains depending on your account type (for example, a traditional IRA vs. a Roth). Run the numbers with a tax advisor before making withdrawal decisions.

When the annual rate is 0%, the calculator skips the interest formula and uses simple division instead. In income mode, the payment equals your principal divided by the total number of periods. In future mode, the ending balance equals your principal plus all contributions combined, with no interest added.