Related: Compound interest · EMI calculator · FD calculator · Percentage calculator
How to use the Simple Interest Calculator tool
- Enter the principal and the yearly interest rate.
- Enter the time in years, months or days.
- Read the interest, the total amount and the monthly interest.
Why SaralKit?
- Free forever: no "credits", no trial, no premium tier, no watermark and no daily limit.
- No account, ever: nothing to sign up for. Just open the page and use it.
- No data stored: your files and the numbers you type are processed by your own browser. We never upload, store or see them.
- Works offline: once the page has loaded, most tools keep working without internet.
- Open source: anyone can read the code on GitHub.
Frequently asked questions
What is the simple interest formula?
SI = P × R × T ÷ 100, where P is the principal, R the rate per year and T the time in years. Total amount = P + SI.
What is the simple interest on ₹1 lakh at 8% for 3 years?
₹1,00,000 × 8 × 3 ÷ 100 = ₹24,000, so the total amount is ₹1,24,000.
Where is simple interest used?
Personal lending between friends and family, some short-term loans, many school maths problems, and interest on some government savings schemes paid out (not reinvested) every year.
How do I enter months or days?
Choose months or days in "Time in" and the calculator converts them to years (days are divided by 365).