Compound Interest Calculator
Enter a starting amount, annual interest rate, term and compounding frequency to see how your money grows over time.
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Optional. Leave as 0 if you won't add money regularly.
How It Works
Unlike simple interest, compound interest is calculated on the principal plus any interest already earned, so growth accelerates over time rather than staying linear.
Formula
A = P × (1 + r/n)^(n×t), where P is the principal, r is the annual interest rate, n is the number of times interest compounds per year, and t is the number of years.
Example
1,000 at 5% annual interest compounded monthly for 10 years grows to approximately 1,647.
Frequently Asked Questions
- Does compounding frequency matter?
- Yes — more frequent compounding (e.g. monthly vs. annually) results in slightly faster growth for the same nominal annual rate, since interest starts earning its own interest sooner.
- Can I include regular monthly contributions?
- Yes, enter a monthly contribution amount and it will be added to the growth calculation alongside the initial principal.
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