Calculate simple interest and ending balance from principal, annual rate, and time without compounding.
Simple interest formula
Simple interest is calculated only on the original principal. Earned interest does not become part of the principal for later periods.
Interest = principal × annual rate × years Ending balance = principal + interest
Simple versus compound interest
With the same positive rate and a period longer than one year, compounding usually produces a larger ending balance because earlier interest also earns interest.
Frequently asked questions
Does this calculator compound interest?
No. Interest is always calculated from the original principal.
Are taxes and fees included?
No. The result is before taxes, fees, and any product-specific rounding.
Can I use months?
Convert months to years by dividing by 12, such as 18 months = 1.5 years.