Simple Interest Calculator
Enter principal, rate and time to get the simple interest and total amount instantly. For school problems and small loans.
Quick answer
₹1 lakh, 7%, 3 years: interest ₹21,000.
How it is calculated
- Simple interest = principal × rate × time ÷ 100.
- 1,00,000 × 7 × 3 ÷ 100 = 21,000.
- Total = principal + interest.
Worked example
₹1,00,000 at 7% a year simple interest for 3 years. Interest is ₹21,000 and the total is ₹1,21,000.
| Principal | ₹1,00,000 |
| Rate | 7 % / yr |
| Time | 3 years |
| Interest | ₹21,000 |
| Total amount | ₹1,21,000 |
Formula
Interest = P×R×T/100 Total amount = P+P×R×T/100
Good to know
- Bank FDs use compound interest; use the compound interest calculator for those.
- Convert months to years: 6 months = 0.5 year.
Questions people ask
What is the simple interest formula?
SI = P × R × T ÷ 100, where P is principal, R the yearly rate and T years.
Simple vs compound interest?
Simple interest is only on the principal; compound interest also earns interest on interest.
How about “rupees per hundred” interest?
Use the Desi byaj (rupaye saikda) calculator.
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Updated 13 Nov 2026 · Desktop N Calculator v1.2.0