Simple Interest Calculator

Calculate simple interest and total amount for loans and deposits.

₹1,000₹1,00,00,000
% p.a.
136
yr
140
Total amount
₹1,40,000
Principal
₹1,00,000
Simple interest
₹40,000

About the Simple Interest Calculator

Simple interest is charged only on the original principal, never on accumulated interest. It is used for many short-term loans, some informal lending, and certain post-office schemes. The AlarmDaddy Simple Interest Calculator gives you the interest amount and the total repayable for any principal, rate, and time.

Enter the principal, the annual rate, and the time in years. The calculator returns the simple interest and the total amount. It is the simplest of all interest calculations, but still useful for cross-checking hand-loan terms, short bridge loans, and comparing against the compound-interest alternative.

How to use this calculator

  1. 1Enter the principal amount.
  2. 2Enter the annual interest rate.
  3. 3Enter the time period in years.
  4. 4Read the simple interest and total amount.

The formula

SI = (P × R × T) / 100

Where P is the principal, R is the annual rate of interest, and T is the time in years. The total amount payable is P + SI. Unlike compound interest, the interest each year stays the same.

Frequently asked questions

Simple interest is common in short-term personal lending, some vehicle loans quoted on a flat-rate basis, and a few post-office schemes. Most bank loans use reducing-balance (compound) interest.