Compound Interest Calculator

See how savings grow with compound interest.

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Grow your money with compound interest

Compound interest pays you interest on your interest, so a balance grows faster the longer it sits. Enter the starting principal, the annual rate, the number of years and how often interest is compounded each year to see the final balance and the total interest earned. Compounding monthly beats compounding annually at the same rate.

Why time matters most

The effect snowballs, so adding a few extra years to the timeline often increases the result more than nudging the rate up.

Frequently asked questions

What does compounding frequency mean?

It is how many times a year interest is added to the balance. Monthly compounding (12 times a year) grows money slightly faster than annual compounding at the same rate.

What is the compound interest formula?

Final balance equals principal times one plus the rate divided by frequency, raised to the power of frequency times years.