Project how savings or an ETF plan grow with compound interest. Set a starting amount, monthly contribution, return and duration, and watch the balance grow year by year.
How to use the Compound Interest
Enter your starting amount, monthly contribution, expected return and number of years.
See the final balance split into what you invested and the interest earned.
Use the chart to watch the balance grow year by year.
Frequently asked questions
Compound interest is interest earned on both your contributions and previously earned interest. Over long periods this compounding drives most of the growth.
Contributions are added at the start of each month and the balance is compounded monthly, which matches how many savings plans and ETF savings plans work.
Returns are never guaranteed. A broad global stock ETF has historically averaged roughly 6 to 8 percent per year before inflation over long horizons, but any given period can differ a lot.
No. The projection is before taxes, fees and inflation. Treat the result as a gross estimate and plan a margin for those factors.
This compound interest calculator shows how a one-off amount plus regular monthly contributions can grow over time at a constant annual return. It separates the total you invested from the interest earned, so you can see the effect of compounding.
It is built for savings and ETF savings-plan planning, with a year-by-year chart of the balance. Calculations run in your browser; returns are assumptions, not guarantees.
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