Compound Interest Calculator
See how time, regular contributions and compound growth can work together. Adjust the rate, time horizon and contribution schedule to compare different saving scenarios.
Use Money Compounding Calculator →How our calculator estimates workWhat the compound interest calculator does
The tool grows the starting balance at the rate and compounding frequency you choose, then adds recurring contributions according to their timing. It separates money contributed from growth generated by the assumed rate.
Information you can enter
- Starting balance and monthly contribution
- Annual interest or return rate
- Compounding frequency, years and contribution timing
How to use it
- Enter the amount you already have and how much you plan to contribute each month.
- Choose an annual rate, compounding frequency and number of years.
- Calculate to see the final balance, total contributions and estimated growth.
What can change the result
Compounding has more periods to work over a longer horizon.
Regular additions can become a large part of the final balance, especially when started early.
Higher assumed returns create higher projections, but real investment returns are not guaranteed and can vary.
Frequently asked questions
What is compound interest?
Compound interest means growth is calculated on the original principal plus previously accumulated interest or returns.
Does compounding frequency matter?
Yes. With the same stated annual rate, the frequency and the calculator's periodic-rate conversion can affect the projected balance.
Can I use this for investments?
You can use it for general growth scenarios, but investment returns are uncertain and actual results can include taxes, fees and periods of loss.