NO. T-0603 · Wealth & Investing
Compound Interest Calculator
- Free · no signup
- Runs in your browser
About this tool
See how your money grows with monthly contributions and compounding.
Compounding is the reason patient investors get rich: returns earn their own returns. Enter a starting amount, a monthly contribution and an expected annual return to see exactly how much your portfolio could be worth — and how much of it is pure interest.
How to use it
- 01Enter your starting balance and how much you plan to add each month.
- 02Set an expected annual return and the number of years you will invest.
- 03Read your final balance and compare contributions vs. interest earned.
Monthly compounding
Interest and contributions are applied every month, like a real brokerage account.
Year-by-year chart
Visualise when interest overtakes your own contributions.
Shareable scenario
Every input is saved in the link — send it to a partner or advisor.
Frequently asked questions
What return should I use?
Broad stock market indexes have historically returned roughly 7–10% per year before inflation. Use a conservative number (5–7%) for planning.
Does this include inflation or taxes?
No. Results are nominal and pre-tax. Use the inflation calculator to convert a future amount into today's purchasing power.
How often is interest compounded?
Monthly. Your contribution is added and the monthly rate (annual rate ÷ 12) is applied each month.
Guetix · Custom
Need a custom financial dashboard?
I build private portfolio trackers and client-facing calculators for advisors and family offices.
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Results are estimates for informational purposes only and are not financial, tax or legal advice.