Simple Interest Calculator

Calculate simple interest using the formula I = P x R x T (Principal x Rate x Time).

Total Interest
Total Amount (P + I)
Monthly Interest
Daily Interest

Simple Interest Formula

I = P x R x T

  • I = Interest earned
  • P = Principal (initial amount)
  • R = Annual interest rate (as decimal)
  • T = Time in years

Simple vs Compound Interest

FeatureSimple InterestCompound Interest
Interest onPrincipal onlyPrincipal + accumulated interest
GrowthLinearExponential
Common useShort-term loans, bondsSavings, investments, mortgages

Frequently Asked Questions

When is simple interest used?
Simple interest is commonly used for short-term loans, auto loans, some personal loans, and certain bonds. It is straightforward and results in lower total interest than compound interest over the same period.