Free tool

Compound Interest Calculator

Estimate how an initial investment plus regular monthly contributions can grow through the power of compounding.

Adjust the inputs below to see your projected ending balance, total interest earned, and year-by-year growth.

A young adult reviewing her investment plan at home
$
$
%
years
Ending balance$124,379
Total interest earned$71,379
Total contributions$53,000
Time invested20 years
InterestContributions
$7,840
$14,151
$21,407
$29,750
$39,343
$50,373
$63,055
$77,637
$94,404
$113,682
$124,379
Yr 1
Yr 5
Yr 9
Yr 13
Yr 17
Yr 20

This calculator is for educational purposes only and does not constitute financial advice. Results are illustrative and based on the inputs selected. Actual results may vary based on market performance, contribution timing, fees, taxes, and inflation. Finelo does not guarantee any investment outcome.

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Frequently asked questions

How does compound interest work?
Compound interest is interest earned on both your original investment and on the interest that investment has already accumulated. Over time, this compounding effect can significantly accelerate growth compared to simple interest.
What's a realistic interest rate to use?
There is no single interest rate that is appropriate for every situation. The rate you choose is an assumption, not a prediction or recommendation. Try several rates to see how sensitive your projection is to this assumption — actual returns may vary and may be negative.
Does this calculator account for taxes or fees?
No. This calculator shows a simplified, pre-tax, pre-fee projection for educational purposes. Real investment returns will be affected by fees, taxes, and market volatility.
How often is interest compounded in this calculator?
This calculator applies the selected annual rate monthly for calculation purposes. Actual compounding frequency depends on your specific account or investment.

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