Calculate simple interest and total amount for any principal, rate, and time period. Compare with compound interest to see the difference.
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The original amount being lent or invested.
Annual percentage rate from the loan or investment agreement.
Choose years, months, or days. The calculator converts automatically.
See how much extra you would earn with compound interest at the same rate.
Simple interest is calculated only on the original principal:
P = Principal R = Annual rate % T = Time in years
Unlike compound interest, SI does not earn interest on interest. This makes it predictable and easier to calculate — but lower-yielding over long periods.
Simple interest is calculated only on the original principal — not on accumulated interest. Formula: SI = P × R × T ÷ 100. Used for short-term personal loans and some fixed income instruments.
Simple interest is linear — same amount every period. Compound interest grows exponentially because each period earns interest on previous interest too. Over 10+ years the gap becomes very significant.
Car loans, personal loans, and some government schemes use simple interest. Most savings accounts and mutual funds use compound interest.
Use T = 0.5 years. SI = P × R × 0.5 ÷ 100. Or use the Months toggle and enter 6 directly.
Simple interest = P × R × T / 100 = 10,000 × 8 × 3 / 100 = Rs 2,400. Total amount = Rs 12,400.