Compound interest calculator

Final balance -
Interest earned -
Total contributions -
APY -
Months -
Frequency -

Estimates are educational and do not predict investment returns, taxes, fees, inflation, or account rules.

See examples

Savings growth

Estimate how a starting balance and regular monthly deposits can grow over time.

Rate comparison

Change the annual rate or compounding frequency to compare long-term outcomes.

Contribution planning

Adjust monthly contributions to see how much of the final balance comes from deposits and interest.

About this helper

This calculator estimates compound growth from a starting amount, annual rate, time, compounding frequency, and optional monthly contribution. It is educational and does not predict real investment performance, taxes, fees, inflation, or account rules.

Is this investment advice?

No. It is an educational calculator and does not recommend investments or predict real returns.

Are my amounts uploaded?

No. The calculation runs in your browser and the site does not receive the amounts you type.

When are monthly contributions added?

Monthly contributions are added at the end of each month in this estimate.