🔄 Annuity Calculator
An annuity turns a stream of equal payments into a lump sum through compounding. This calculator values an ordinary annuity — payments at the end of each month — growing at your annual rate for the full term.
The gap between what you paid in and the final value is the interest the annuity earned for you, which the results break out separately.
How to use this calculator
Enter the monthly payment, annual rate and number of years to find the future value of the annuity.
- Enter the Monthly payment into the annuity.
- Type the Annual interest rate as a percentage.
- Set the Years of payments.
- Press Calculate to see the future value, total paid in and interest earned.
Frequently asked questions
What kind of annuity does this model?
An ordinary annuity: equal payments at the end of each month, compounding monthly. Paying $500 a month at 6% for 20 years grows to about $231,020.
How much of the total is interest?
The example's 240 payments total $120,000, so about $111,020 of the final value is interest earned through compounding.
What if the rate is zero?
Then there is no growth and the future value is simply the payment times the number of payments.
Does it handle payments at the start of the month?
No, it assumes end-of-month payments. Start-of-month payments would earn slightly more.