Free tool
Compound interest calculator
With compound interest, the interest earns interest too. Example: $10,000 at 5% a year plus $100 a month grows to $31,998 in 10 years – $9,998 of it is interest.
How it is calculated
End value = P · (1 + i)n + C · ((1 + i)n − 1) / i, with P = starting amount, C = monthly contribution, i = annual rate / 12, n = number of months. Interest is credited monthly, the contribution is added at the end of each month. Costs and taxes are not included.
Frequently asked questions
What is compound interest?
Interest earned on interest that has already been credited. The longer the money stays invested, the larger its share of the end value.
How often is interest credited here?
Monthly, at one twelfth of the annual rate. With annual crediting the end value is slightly lower.
Are costs and taxes included?
No. The calculator shows the plain arithmetic; fees, taxes and changing returns alter the result.
DESK is a research tool. This calculator shows arithmetic, not a recommendation: it is not investment, tax or financial advice, and past values say nothing about the future.
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DESK is a research tool and not investment advice.