Simple Interest Calculator

Enter principal, rate and time to instantly calculate simple interest and total amount.

Runs in browser
Interest Earned
—
Total Amount
—

Simple Interest Formula

I = P × r × t

I = P × r × t — where P is principal, r is annual rate (decimal), t is time in years. Total = P + I.

How to use?

  1. 1
    Enter the principalType the starting amount you want to invest or lend.
  2. 2
    Set rate and timeEnter the annual interest rate (%) and the duration in years.
  3. 3
    Read the resultClick Calculate to instantly see the interest earned and the total amount.

FAQ

What is simple interest?
Simple interest is calculated only on the original principal. It does not compound — interest is never added to the principal to earn further interest. Formula: I = P × r × t.
What is the difference between simple and compound interest?
With simple interest, the interest is always calculated on the original principal. With compound interest, interest is periodically added to the principal and itself earns interest. Compound interest grows faster over time.
Where is simple interest used?
Simple interest is commonly used for short-term loans, car loans, instalment purchases, savings bonds, and some personal loans. It is straightforward to calculate and transparent for the borrower.

Simple Interest Calculator

Simple interest is the most basic method of calculating the cost of borrowing money or the return on an investment. Unlike compound interest, it is always calculated on the original principal amount only, making it easy to understand and predict. Use this calculator for short-term loans, savings bonds, or any fixed-rate financial product.

Comments