How to use Compound Interest Calculator
- Enter starting principal, rate, and time period.
- Add monthly contributions if applicable.
- Review projected future value and growth.
Worked examples
Concrete numbers and cases you can check against the tool above.
$200 per month for 10 years at 7%
Contributions total $24,000. Compounded monthly at 7% annual, future value is roughly $34,600 (about $10,600 of growth). Starting with $5,000 already saved adds more, because that lump sum compounds the whole decade. Rate assumptions are not a forecast.
When to use Compound Interest Calculator
Compound growth rewards time and consistent contributions. Projecting future value makes savings goals concrete instead of abstract.
Common use cases
- Estimate a rainy-day fund with monthly deposits.
- Illustrate compound interest for a classroom.
- Compare contribution amounts toward a target balance.
- Sketch long-term growth at a chosen annual rate.
Inputs and outputs
- Currency amounts, annual rates (%), time periods
Privacy
This tool runs entirely in your browser. Your data never leaves your device β nothing is uploaded to our servers.
Frequently asked questions
- How often does interest compound?
- The calculator uses the compounding frequency shown in the UI (for example monthly). Match it to your account when possible.
- Does this include taxes or fees?
- Usually no. It is a growth estimate before taxes, fees, or market volatility.
- Are inputs stored?
- No.