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Simple Interest Calculator for Loans

Quickly calculate simple interest per day, month, or year for loans, savings, or private lending.

Simple Interest Calculator

%
Yr

Principal Amount

10,000

Total Interest

4,000

Total Amount

14,000

Simple Interest Basics

Simple interest is calculated only on the principal amount involved in an investment or loan. It's calculated as a percentage of the principal for a certain period of time.

The Formula

A = P(1 + rt)
Where: A = Total Amount, P = Principal, r = Annual Interest Rate, t = Years

Simple Interest Explained

When to Use Simple Interest?

Simple interest is most commonly used for short-term loans, car loans, or informal lending between friends and family. If you are looking for an interest calculator for friend loan, this is the right tool. It calculates interest only on the principal amount, making it fair and easy to understand.

Daily vs. Annual Calculation

Sometimes you need to charge or pay interest for just a few days. Our calculator helps you understand the annualized cost. To calculate simple interest per day manually: (Principal × Rate × 1) / 36500.

Simple Interest vs. Compound Interest

Simple Interest: Best for borrowers. You pay less interest over time.
Compound Interest: Best for investors. You earn interest on interest.

For long-term investments like mutual funds, use our Compound Interest Calculator instead.

Need more complex calculations?

Try our other calculators for SIPs, EMIs, and Compound Interest to get a complete picture of your financial health.