Free Online Annuity Calculator
Enter a starting amount, how much you add each period, your expected annual return, and how long you save. You get an estimated future value for a stream of equal payments (an ordinary annuity).
Models an ordinary annuity: equal payments at the end of each period, compounded at the rate you enter.
What this annuity calculator shows
An annuity is a series of equal payments at regular intervals—like monthly 401(k) contributions or a fixed loan payment. This calculator estimates the future value of money you already have plus payments you make over time, compounded at the rate you enter.
It assumes payments at the end of each period (ordinary annuity). Payments at the start of each period would grow slightly faster; this tool uses the more common end-of-period timing.
Use a conservative return for planning (e.g. 4–6% for long-term stock/bond mixes). Actual returns vary year to year.
Worked examples
Sample numbers you can try in the calculator above. Your lender's quote may differ slightly.
Steady monthly saving
Starting balance plus monthly deposits compound each month. Small increases in contribution or years make a big difference over time.
$10,000 start · $500/month · 5% · 20 years
Result: About $318,000 future value
Starting from zero
You do not need a large lump sum to build savings. Consistent monthly deposits are often how retirement accounts grow.
$0 start · $400/month · 6% · 30 years
Result: About $402,000 future value
Higher contribution, shorter horizon
Doubling the monthly payment speeds growth more than a slightly higher rate over a short window.
$5,000 start · $1,000/month · 7% · 10 years
Result: About $178,000 future value
Quarterly deposits
Change contribution frequency in the dropdown. Fewer, larger payments per year slightly change the total compared with monthly saves at the same annual amount.
$20,000 start · $1,500/quarter · 5% · 15 years
Frequently asked questions about the annuity Calculator
What is an annuity?
A series of equal payments at regular intervals—common in loans, pensions, and savings plans. This page focuses on growing those payments into a future balance.
Ordinary annuity vs annuity due?
Ordinary annuity: payments at period end. Annuity due: payments at period start. End-of-month contributions match the ordinary annuity model used here.
What rate should I enter?
Use your expected average annual return for investments, or the loan APR for debt. For retirement planning, many people use 4–7% depending on risk tolerance—not a guarantee.
Is this only for retirement?
No. Use it for any repeating cash flows: SIP-style investing, sinking funds, or comparing how much you'll have if you raise your monthly contribution.