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Simple Interest Calculator

Calculate simple interest on your loans or investments. Easy to use online tool with formula and worked examples.

Introduction

The Simple Interest Calculator is a straightforward tool to determine the interest charged or earned on a principal amount over a specific period at a fixed rate.

How to Use

Input the principal amount, the annual interest rate, and the time period in years. Click calculate to see the total interest and the final amount.

Formula

Formula: SI = (P × R × T) / 100, where P is Principal, R is Rate per annum, and T is Time in years.

Examples

Example: Invest $1000 at 5% for 2 years. SI = (1000 × 5 × 2) / 100 = $100. Total = $1100.

Results Explained

The results show the Total Interest earned/charged and the Final Balance (Principal + Interest).

Frequently Asked Questions

What is simple interest?

Simple interest is calculated only on the principal amount of a loan or deposit.

How is it different from compound interest?

Compound interest is calculated on the principal and also on the accumulated interest of previous periods.

What formula is used?

The formula is SI = (P × R × T) / 100.

Can I calculate for months?

Yes, convert months to years by dividing the number of months by 12.

Is this used for bank savings?

Most modern bank accounts use compound interest, but some simple loans and short-term deposits use simple interest.

Is the rate per month or year?

The standard rate used in the formula is the Annual Percentage Rate (APR).