Compound Interest Calculator

Project how your money could grow with monthly contributions, compounding, and time.

This calculator helps you estimate future value, growth earned, and a rough retirement income projection from your investment strategy.

Key idea: small monthly contributions can look quiet today. Over enough time, compounding can do the heavy lifting.

Calculator inputs

Run your projection

Enter your starting amount, monthly contribution, monthly return, and time horizon.

Initial investment ($)

Monthly contribution ($)

Interest rate (% per month)

Investment period (months)

Projection area

Waiting for inputs

Enter your numbers and run the calculation to see projected future value, total invested, estimated gains, and a simple retirement-income view.

Future value

Calculated after you run the tool.

Growth earned

Shows how much compounding added.

Retirement income

Simple monthly estimate at a 4% rate.

How this works

This calculator assumes monthly compounding and end-of-month contributions.

Results are estimates for educational purposes only and should not be treated as financial advice.

Why this matters

Compounding shows how time, consistency, and rate of return interact. Small monthly decisions can create dramatically different outcomes later.