Simple Interest Calculator — Calculate SI
Calculate simple interest on any principal amount. Find total interest earned and maturity amount using the SI formula.
By SwiftCalcTools Editorial Team · Formula verified
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How to Use Simple Interest Calculator
- 1Enter the required values in the input fields above.
- 2Click the Calculate button or results update instantly as you type.
- 3View your results in the output panel below the inputs.
- 4Adjust any values to recalculate instantly.
Frequently Asked Questions
Simple interest is calculated only on the original principal amount, not on accumulated interest. SI = P × R × T / 100. It's used in short-term loans, car loans (in some countries), and personal loans where interest doesn't compound.
For borrowers: simple interest is better (you pay less). For investors: compound interest is better (you earn more). Example: ₹1L at 10% for 5 years — SI gives ₹1,50,000 total. CI (annually) gives ₹1,61,051. The gap widens dramatically over longer periods.
Simple interest is used in: Government bonds (interest paid periodically), recurring deposits (partial), some gold loan products, short-term personal loans, trade credits, and post-dated cheque transactions. Most banks and financial products in India use compound interest.