Compound Interest Calculator

See how your money grows when interest earns interest — with regular contributions and a year-by-year breakdown.

Runs in your browser — nothing is uploaded

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For information only — not financial advice. Real results depend on fees, taxes and market conditions.

How to use Compound Interest Calculator

  1. Enter your starting amount and monthly contribution.
  2. Set the interest rate, years and compounding frequency.
  3. Read the future value and explore the yearly chart and table.

Questions

What is compound interest?

Interest calculated on both your original money and the interest already earned. Over long periods it grows much faster than simple interest.

Does compounding frequency matter much?

A little: monthly compounding earns slightly more than annual at the same rate. The effective annual rate shown makes the difference visible.