Interest Calculator
Project how an investment or deposit grows — switch between simple and compound interest and any compounding frequency.
| Year | Balance | Interest that year |
|---|
Estimates only. Figures are nominal and exclude taxes, fees and inflation. Compounding shown is applied at the selected frequency.
Frequently asked questions
What is the difference between simple and compound interest?
Simple interest is calculated only on the original principal for the whole period. Compound interest is calculated on the principal plus all the interest already earned, so it grows faster the more often it compounds. Most savings, CDs and bonds use compound interest.
How does compounding frequency affect my return?
The more frequently interest compounds, the more you earn, because each round of interest starts earning interest sooner. Daily compounding beats annual, though the difference shrinks as rates get lower. Continuous compounding is the mathematical limit and is shown here for reference.
What is the effective annual rate (EAR)?
EAR converts a nominal rate compounded several times a year into the equivalent yearly rate if it compounded once. It lets you compare a “5% compounded monthly” offer with a “5.1% compounded annually” offer on equal footing — the higher EAR wins.
Does this account for taxes or inflation?
No. The figures are gross of taxes and do not adjust for inflation. If your interest is taxable, your real return is lower; if inflation runs above your rate, your purchasing power can still decline even as the balance grows.