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Calculate simple interest, interest earned, and total maturity amount instantly.
Unlike compound interest where gains accumulate on previously earned returns, Simple Interest calculates linear accrual exclusively on the original initial principal ($SI = (P \times R \times T) / 100$). It is standard for short-term promissory notes, auto-debit penalty calculations, and informal lending agreements.
Calculate simple interest, interest earned, and total maturity amount instantly.
Over a 20-year horizon on a ₹10 Lakh principal at 10% per annum, Simple Interest yields ₹20 Lakhs in total interest (₹30 Lakhs total), whereas Compound Interest generates ₹57.27 Lakhs in interest (₹67.27 Lakhs total) — demonstrating a ₹37.27 Lakh compounding advantage.
Enter the amount of money invested or borrowed.
Enter the annual interest rate percentage.
Specify the duration in years.
See interest earned and total maturity amount.
SI = (P × R × T) ÷ 100
Simple Interest is calculated on the original principal amount for the entire investment or loan duration.
Input: Principal: ₹1,00,000, Rate: 8%, Time: 5 Years
Output: Simple Interest = ₹40,000, Total Amount = ₹1,40,000
Simple Interest is interest calculated only on the original principal amount throughout the investment or loan period.
Simple Interest is calculated using the formula SI = (Principal × Rate × Time) ÷ 100.
Simple Interest is calculated only on the principal amount, while Compound Interest is calculated on both principal and accumulated interest.
Simple Interest is commonly used for short-term loans, educational examples, and basic financial calculations.
Yes, it can estimate interest payable on loans that use simple interest calculations.
Simple interest applies the rate only to the original principal, so the interest amount does not itself earn interest. It is commonly used for short-term estimates, certain loans, promissory notes, and classroom problems. Confirm the lender's actual calculation method before relying on an estimate.
The formula SI = P × R × T / 100 assumes an annual percentage rate and time measured in years. Convert months to years by dividing by 12. For ₹20,000 at 8% per year for 18 months, T is 1.5 and the interest is ₹2,400.
The result does not include compounding, processing fees, late charges, taxes, changing rates, or repayment schedules. Use an EMI or compound-interest calculator when those features apply.
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This page is maintained through a documented review of calculation logic, worked examples, assumptions and financial limitations. DevCalc is founded and maintained by software engineer Aditya Singh. Important financial, health, legal and government figures should still be confirmed with the relevant official source.
This calculator and its guidance are for general educational purposes only and do not constitute financial, investment, or tax advice. Verify figures with a qualified professional before making financial decisions.
