Simple Interest Calculator

I = P × R × T, computed instantly with the total repayment amount.

Quick answer: Calculate simple interest online safely. Find interest earned or owed quickly using the classic I = P × R × T formula.

$
%
yrs
Interest$900
Total amount$5,900

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The classic I = PRT calculation: interest earned or owed when it does not compound.

How it works

  1. Input the principal amount (the initial sum).
  2. Input the annual interest rate and timeframe.
  3. Read the calculated total interest using standard simple math.

Frequently asked questions

Simple vs compound — which applies to me?

Most savings accounts and credit cards compound. Some personal loans, car loans, and bonds use simple interest. Check your agreement.

Can time be in months?

Enter fractions of a year: 18 months = 1.5 years.

Why is my bank quote different?

Banks may use day-count conventions (360 vs 365 days) that shift the result slightly.

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