Simple Interest Calculator
Calculate interest that is charged only on the original principal — common in short-term personal lending and textbook problems.
Simple interest
₹21,000.00
- Principal
- ₹1,00,000.00
- Total amount
- ₹1,21,000.00
All calculations run in your browser. The numbers you enter are not sent or stored anywhere. Privacy policy
How to use the Simple Interest Calculator
- 1Enter the principal, annual interest rate and time.
- 2Choose whether time is in years, months or days.
- 3Read the interest and total amount.
Supported formats and limits
- Time up to 100 years. Days are converted using a 365-day year.
Formula
Simple interest = P × R × T ÷ 100, where P is the principal, R the annual rate in percent and T the time in years. Total amount = P + interest.
Most bank deposits and loans use compound or reducing-balance interest instead; use the Compound Interest or EMI calculator for those.
Results are estimates for planning and learning. They are not financial, tax or legal advice — confirm important figures with your bank, a chartered accountant or the official source.
Frequently asked questions
How is time in months converted?
Months are divided by 12 to get years, and days by 365.