Simple Interest Calculator
Calculate simple interest on a principal amount — no compounding.
Your inputs
Simple interest = principal × rate × time ÷ 100. Unlike compound interest, it's calculated only on the original principal every period.
Estimates only. Figures are indicative and do not constitute financial advice.
About the Simple Interest Calculator
"Simple interest calculator," "SI calculator," or "sada byaj calculator" (सादा ब्याज, the Hindi term for the same thing) is searched for exactly the calculations that don't involve compounding — some loans, certain short-term deposits, and plenty of school and exam-prep math problems use simple interest, where interest is calculated only on the original principal, not on accumulated interest.
The formula is refreshingly straightforward: interest equals principal multiplied by rate multiplied by time, divided by 100 — sometimes remembered as the SI = PRT/100 formula from school. This calculator applies that directly to give you the interest earned and the total amount, and it's a genuinely useful contrast to keep alongside our compound interest calculator — comparing the two on the same numbers makes clear just how much compounding adds over longer periods, since simple interest grows linearly while compound interest accelerates. It's also exactly the calculation many students and exam aspirants (banking and government exam prep in particular) need for practicing SI/CI problems quickly, and it's the same math some lenders use on certain flat-rate personal or consumer loans, where the true effective rate ends up higher than the stated one once you account for how it's applied over the full loan tenure.
How to use this calculator
- Enter the principal amount.
- Enter the interest rate.
- Enter the time period in years.
- See your interest earned and total amount.
Frequently asked questions
›What is the simple interest formula?
Simple Interest = Principal × Rate × Time ÷ 100, calculated only on the original principal for the entire period.
›What is the difference between simple and compound interest?
Simple interest is calculated only on the original principal every period, while compound interest is calculated on the principal plus any interest already earned, causing it to grow faster over time.
›Which financial products use simple interest in India?
Some short-term loans and specific deposit products use simple interest, though most mainstream savings products (FD, RD, PPF, savings accounts) use compound interest instead.
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Read the full guide
Simple Interest Calculator: Formula, Examples & When It Applies