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Interest Calculator

Compute simple or compound interest on a principal over time.

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About the Interest Calculator

The Interest Calculator shows how a principal grows over time with simple or compound interest. For compound interest you choose how often interest is added: yearly, quarterly, monthly or daily.

Simple interest is earned only on the original amount; compound interest is also earned on interest already added. Everything runs in your browser with JavaScript. Nothing you type is uploaded to our server, so it is safe to use with private data.

How to use it

  1. Enter the principal.
  2. Enter the annual rate and the term in years.
  3. Choose simple or compound interest and the compounding frequency.
  4. Select Calculate interest.

Common uses

  • Estimating savings account growth.
  • Comparing deposits that compound at different frequencies.
  • Explaining the difference between simple and compound interest.

Tips

  • More frequent compounding gives a slightly higher result at the same rate.
  • Results ignore taxes, fees and inflation.