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Compound interest calculator

Contributions are added at the end of each month and growth compounds monthly. Returns aren't guaranteed; try a few rates to see a range.

Starting amount ($)Monthly contribution ($)Yearly growth rate (%)Years

Do this every month in a spreadsheet

Savings Goals Tracker Spreadsheet: Set targets, log deposits to each goal, and see saved, remaining and percent complete update instantly.

Excel and Google Sheets, formulas already set up. Instant download.

What rate should I use?

Use a conservative number. Savings accounts pay a few percent; long-run stock market returns have averaged higher but vary a lot year to year.

Why does starting early matter so much?

Growth earns its own growth. The last years of a long period add the most, so extra years at the start make a big difference.