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Compound interest calculator

Enter a starting amount, a monthly contribution, the interest rate and the number of years to see what your money could grow to.

Future value

54,713.58

Total contributed
34,000.00
Interest earned
20,713.58
Effective annual rate (APY)
7.229%

Calculated on this page. Nothing you type is sent anywhere.

How it works

Compound interest pays interest on earlier interest as well as on what you put in. The starting amount grows as P × (1 + r/n)^(n × t), where r is the yearly rate, n the number of compounding periods a year and t the number of years.

Each monthly contribution grows at the same rate from the month it is added. The effective annual rate (APY), (1 + r/n)ⁿ − 1, shows what the quoted rate is really worth once compounding is counted. The rate is assumed constant, and taxes and fees are not included.

Read the guideInvestment Calculator Guide — Plan Compound Growth

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