Simple Interest Calculator

Calculate simple interest for any principal amount, rate of interest, and time period.

Simple Interest

₹1,000₹10.00 Cr
0.1%30.0%
1 Yr40 Yr
Total Amount₹1,40,000
Principal invested₹1.00 L
Interest earned₹40,000
Principal71%
Principal
Interest
Year-by-Year Growth
YearPrincipalInterest (Cumulative)Total
1₹1.00 L₹8,000₹1.08 L
2₹1.00 L₹16,000₹1.16 L
3₹1.00 L₹24,000₹1.24 L
4₹1.00 L₹32,000₹1.32 L
5₹1.00 L₹40,000₹1.40 L

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What is simple interest?

Simple interest is a method of calculating interest where the interest charge is applied only to the original principal amount. Unlike compound interest, you do not earn "interest on interest". The interest amount remains constant every year.

The formula is: Simple Interest = P × R × T / 100, where P is the principal amount, R is the annual interest rate, and T is the time in years. The total amount is simply Principal + Interest.

Where is simple interest used?

Simple interest is commonly used in:

Short-term personal loans and consumer finance
Car loans and some education loans in India
Government bonds and certain corporate bonds
Some microfinance and peer-to-peer lending products
Late payment penalties and short-term credit facilities

Simple interest vs compound interest

The key difference is that simple interest is calculated only on the original principal, while compound interest is calculated on the principal plus accumulated interest. For short periods (1-2 years), the difference is small. Over longer periods, compounding creates exponentially larger returns. Most savings accounts, FDs with reinvestment, and long-term investments use compound interest, while most short-term loans use simple interest.

Frequently asked questions

Simple Interest = P × R × T / 100, where P is the principal amount, R is the annual interest rate, and T is the time in years. Total Amount = P + Simple Interest.
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