How to use the Simple Interest Calculator
- Enter the principal amount.
- Enter the yearly rate of interest.
- Enter the time and choose years, months or days.
About this tool
Simple interest is charged only on the original principal, never on interest already earned. The formula is SI = P × R × T ÷ 100, where P is the principal, R the yearly rate in % and T the time in years; the total amount is P + SI. If the time is in months, T = months ÷ 12; if it is in days, T = days ÷ 365.
For example, ₹50,000 at 10% a year for 2 years earns ₹10,000 simple interest, so the total is ₹60,000. Simple interest is common for short-term personal loans between people, some gold and vehicle loans, and school maths problems; bank deposits and most loans use compound interest instead.
Frequently asked questions
What is the simple interest formula?
SI = P × R × T ÷ 100, with T in years. Amount = P + SI.
How do I calculate simple interest for months?
Divide the months by 12. For ₹50,000 at 10% for 6 months: 50,000 × 10 × 0.5 ÷ 100 = ₹2,500.
What is the difference between simple and compound interest?
Simple interest is calculated on the principal only. Compound interest is calculated on the principal plus interest already added, so it grows faster.