Compound Interest

Project future value, interest earned, and contribution growth over time. Free online calculator with formulas and step-by-step solutions.

Key formula

future value with compounding and contributions

About this tool

Compound growth is powerful because time, rate, and regular contributions amplify one another. This calculator helps users see that long-term results come not from one big number alone, but from the interaction between repeated growth and repeated input.

How to use this calculator

1. Enter the main planning inputs first, such as amount, rate, term, or contribution.
2. Check the assumptions behind the result, especially rate, taxes, fees, or timing.
3. Use the output as a planning baseline rather than a final legal or lender-approved figure.
4. Review the formula steps so you can see exactly how the estimate was constructed.