Compound Interest Calculator
Enter the principal, annual rate, term, compounding frequency, and monthly contribution to calculate the final amount and interest in real time. All calculations happen in your browser.
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Enter the principal, rate, and term to see the result.
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Final amount
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Amount invested
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Interest (gain)
How to use
- Enter the principal, annual rate (%), and term (years).
- Choose the compounding frequency and enter a monthly contribution if any.
- The final amount, amount invested, and interest are shown in real time.
Frequently asked questions
How is compound interest calculated?
The final amount is principal × (1 + rate/compounds)^(compounds × term). Interest earns interest, so it grows more than simple interest.
Are monthly contributions included?
Yes. If you enter a monthly contribution, it is compounded monthly and included in the final amount.
Are the values I enter sent to a server?
No. All calculations happen inside your browser, and the values you enter are not sent to any external server.