Compound Interest Calculator · Manual

How to Use the Compound Interest Calculator

Enter a starting amount or regular contribution, an annual rate, a time horizon, and the rate/contribution settings that match your scenario.

Starting amount and currency

Starting amount is the balance present at time zero. Display currency changes formatting only; it does not perform exchange-rate conversion.

Annual rate and rate type

Choose Nominal annual rate when you want to specify a compounding frequency. Choose APY when the entered percentage already represents effective annual growth.

Years and months

Enter a whole number of years from 0 to 100 and months from 0 to 11. The combined horizon must be greater than zero.

Compounding frequency

Nominal-rate mode supports Annual, Semiannual, Quarterly, Monthly, Weekly, and Daily compounding. APY mode does not apply a second compounding frequency.

Regular contributions

Regular contributions can occur monthly, quarterly, semiannually, or annually. Choose whether each contribution happens at the beginning or end of its contribution period.

Results

Future value is the projected ending balance. Total contributed is the starting amount plus all modeled contributions. Interest earned is Future value minus Total contributed.

Exports

Copy Result summarizes the current projection, CSV exports the growth schedule, and Print / Save PDF uses the browser print dialog. Editing an input makes exports stale until you calculate again.