Retirement

Annuity Calculator

Enter a principal, interest rate and number of periods to find the level payment an annuity pays out each period.

  • Free
  • No sign-up
  • Updated for 2026

Principal, rate & periods

$
%

Enter the principal, rate and periods to see the payment.

Worked example

With these example inputs:

  • Annuity principal$500,000
  • Interest rate5%
  • Number of periods20

Payment per period: $40,121

  • Principal$500,000
  • Total paid out$802,426
  • Periods20

Add this calculator to your site

Free to embed. Copy the snippet below, it drops the live calculator straight into any page.

What this annuity calculator does

This calculator finds your payment per period. You enter a principal, a rate, and the number of periods. The tool then shows the payment in your currency. It turns a lump sum into a steady stream. This is a key planning tool. You can plug in other values. The result helps you plan an income.

What an annuity is

An annuity is a stream of equal payments. It pays out the same amount each period. The payments come from a starting principal. That principal earns a return along the way. So a lump sum becomes a regular income. It is a common retirement tool. It is shown in your currency.

How it is calculated

The tool starts with your principal. It spreads it over the number of periods. It applies your rate to the balance. The payment is set so the fund ends at zero. Each payout is the same size. The calculator does the math for you.

What the result tells you

The result shows your payment per period. A principal of five hundred thousand at five percent over twenty periods pays out a steady sum. A higher rate raises each payment. More periods lower each one. So it shows your regular income. It is a clear end figure.

The role of the rate

The rate sets how hard the fund works. A higher rate means a bigger payment. The principal keeps earning as it pays out. So even a small rate lifts the stream. A lower rate shrinks each payout. So the rate matters a lot here. Patience is richly rewarded.

The role of the number of periods

The number of periods sets how long it pays. More periods spread the fund thinner. So each payment is smaller. Fewer periods mean bigger payouts. But they run out sooner. So you trade size against length. Pick a span that fits your plan.

Total paid out

The tool also shows the total paid out. It adds up every payment over the span. That total beats the starting principal. The extra comes from the rate earned. So the fund pays more than you put in. The longer it runs, the more it adds. Watch the total, not just the period.

How to use it

Enter your principal first. Add the rate and the number of periods. Read your payment per period in your chosen currency. See the total paid out as well. Then change an input and retry. Compare a few rates. Use it to plan an income.

The limits of this calculator

Keep its limits in mind. It assumes a steady rate for the span. Real annuities can carry fees. It does not include tax. The period can be a year or a month. So treat it as a guide. So treat the number with care.

Common mistakes to avoid

A common mistake is mixing up the period. A yearly rate needs yearly periods. Another is ignoring fees and tax. Those shrink the real payout. Some forget the principal runs down. Others assume it lasts forever. A clear number keeps you from these slips.

A final tip

Use this to plan an income. Remember the payment depends on the rate and span. Match the period to your rate. Account for fees and tax apart. Check the total paid out too. Do not assume the fund is endless. Double-checking keeps the figure honest.

Frequently asked questions

How does this annuity calculator work?

It spreads a lump sum into equal payments over a set number of periods at a given rate. A $500,000 principal at 5% over 20 years pays about $40,121 a period.

Is this a guaranteed income?

No. This is a mathematical estimate of level payments, not a quote. Real annuity products include fees, options and provider terms, so treat it as a guide, not a guarantee.