Compound interest calculator
Explore how your money could grow. Adjust the values to explore your numbers.
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How to calculate compound interest
P is the starting balance, C the monthly contribution, r the annual percentage rate ÷ 100 ÷ 12, and n the number of months. At 0%, FV = P + C × n. Assumes monthly compounding and contributions at month-end, with a constant nominal annual rate. Taxes, fees and inflation are excluded; returns are not guaranteed.
A worked example
With starting balance of 10,000, monthly contribution of 200, annual nominal rate (%) of 5, time (years) of 10, future balance is 47,526.55 in your chosen currency. Change the example above to match your situation.
Enter amounts in the same currency and time period. Results display up to two decimal places; calculations use unrounded values. These estimates are for planning and education.
Common questions
When are monthly contributions added?
Contributions are added at the end of each month. Interest compounds monthly using the annual nominal percentage rate divided by 12.
Is the projected balance guaranteed?
No. The projection assumes a constant illustrative rate and excludes fees, taxes and inflation. Actual returns may differ, and investments can lose value.