Simple Interest Calculator

Calculate simple interest using I = P × R × T

Loan / Investment Details

I = P × R × T

Interest = Principal × Rate × Time

%

Results

Enter values to calculate simple interest

Interest by Time Period

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About Simple Interest

Simple interest is calculated only on the original principal — unlike compound interest, it does not earn interest on previously accrued interest. It's commonly used for short-term loans, car loans, and some savings accounts.

Formula Breakdown

I = P × R × T
A = P + I = P(1 + RT)

I = Interest, P = Principal
R = Annual rate (decimal)
T = Time in years

Simple vs Compound

  • Simple interest grows linearly over time
  • Compound interest grows exponentially
  • For short durations, the difference is small
  • Over long periods, compound interest grows much faster