Compound Interest Calculator
Estimate compound growth with contributions, scenarios, a chart, and yearly table.
What this calculator does
Project a starting balance with recurring contributions and selectable compounding frequency, then compare growth scenarios.
Inputs and what they mean
- Starting amount
- — number value.
- Annual interest rate
- — number value.
- Years
- — number value.
- Monthly contribution
- — number value.
- Compounding frequency
- — choice value.
How to use it
- Enter the starting amount and annual rate.
- Set the term, monthly contribution, and compounding frequency.
- Review the estimate, scenarios, yearly table, and chart.
Formula
Balance compounds at the selected frequency: A = P(1 + r/n)^(nt), with contributions added throughout each year.
Worked example
$10,000 at 6% for 10 years
Add $100 monthly to compare contributions with estimated compound growth.
Reading the result
The headline figure is the main answer. Any breakdown underneath shows the parts that make it up, so you can check the working and see what changes when you adjust an input.
Limitations and assumptions
Results depend entirely on the figures you enter and are rounded for display. They are for general information and education, not professional advice.
Common questions
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