How to compute simple interest

1. Enter the principal

   "Principal" is the amount you start with. The tool does no unit conversion — pick a currency and stick to it through all the fields.

2. Annual rate %

   "Annual rate %" is the nominal annual interest rate (e.g. 5 for 5%). Unlike compound interest, this rate is applied straight to the principal — there's no compounding loop here.

3. Years

   "Years" is the duration. Fractional years are fine — 1.5 means 18 months of interest at the stated annual rate.

4. Press Run

   Result returns simpleInterest (principal × rate × years) and total (principal + interest), each rounded to 2 decimal places. For compounding, use compound-interest-calculator instead.