Compound Interest Calculator
See how savings grow with compound interest, including regular monthly deposits. It runs in your browser.
Also searched as: investment calculator · interest calculator · savings growth calculator
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How to use it
- 1
Enter your savings
Add the starting amount and any monthly contribution.
- 2
Add rate and time
Enter the rate, how often it compounds and the number of years.
- 3
See the growth
The final balance, interest earned and what you put in.
Questions about compound interest calculator
What does compounding frequency change?
More frequent compounding earns a little more, as interest is added to the balance more often.
Can I include monthly deposits?
Yes. Add a monthly contribution and it is included in the growth.
Is my information private?
Yes. It is worked out on your device.
Reading the result
The calculator shows the final balance, the interest earned and the amount you put in yourself. As an example, 10,000 to start plus 200 a month at a steady 6 percent compounded monthly grows to about 125,500 after 20 years. You contributed 58,000 of that, so about 67,500 is interest.
The longer the money stays invested, the more of the final figure comes from interest rather than deposits, which is why starting early matters so much.
Keep the assumptions in mind
The tool uses one steady rate for the whole period. Real investments rise and fall, and savings rates change, so treat the result as an illustration, not a promise. Compounding more often earns slightly more, but the rate and the time have far bigger effects than the frequency.