How to use the compound interest calculator
- Enter your starting amount and how much you'll add each month.
- Enter the expected yearly interest rate, the number of years and how often interest compounds.
- See your future balance, total interest earned and a year-by-year chart.
About the Compound Interest tool
Compound interest means you earn interest on your interest. Over long periods the effect is powerful — which is why starting early often matters more than starting big. Use this calculator to compare scenarios, like saving a little more each month or investing for five extra years.
100% free
No limits, no watermarks and no sign-up.
Private
Results are estimates for information only, not financial advice.
Fast
No uploading or waiting in a queue. Results in seconds.
Works everywhere
Windows, Mac, iPhone, Android and Chromebook.
Frequently asked questions
What is compound interest?
It's interest calculated on both your original money and the interest you've already earned, so your balance grows faster every year.
What interest rate should I use?
Use the rate your savings account or investment actually offers. Savings accounts often pay a few percent a year; investment returns vary and are never guaranteed.
What does compounding frequency mean?
It's how often interest is added to your balance. The more often it compounds, the slightly faster your money grows.
Does this include taxes and inflation?
No. Results are before taxes, fees and inflation, so real-world returns will usually be lower.