Simple Interest Calculator

Simple interest is calculated only on the original principal amount using the formula: I = P × R × T, where P is principal, R is annual interest rate (as decimal), and T is time in years. For example, $10,000 at 5% for 3 years: I = $10,000 × 0.05 × 3 = $1,500 total interest. The total amount due is $11,500.

Simple interest is calculated only on the original principal, while compound interest is calculated on principal plus accumulated interest. $10,000 at 5% for 3 years: Simple interest = $1,500 total. Compound interest (annually) = $1,576.25 total. The difference grows dramatically over longer periods—compound interest can yield significantly more.

Simple interest is typically used for: short-term loans, car loans (sometimes), personal loans with fixed terms, some bonds and certificates of deposit, and calculating late payment fees. It's preferred when the loan term is short or when borrowers want predictable, easy-to-calculate interest amounts.

To convert annual rate: Monthly rate = Annual rate ÷ 12. Daily rate = Annual rate ÷ 365 (or 360 for some financial calculations). For a 6% annual rate: Monthly = 6% ÷ 12 = 0.5% per month. Daily = 6% ÷ 365 = 0.0164% per day. Use the appropriate rate based on how interest is charged.

Yes, simple interest benefits borrowers in several ways: 1) You pay less overall compared to compound interest, 2) Interest doesn't grow exponentially over time, 3) Early payments reduce principal immediately (saving future interest), 4) Calculations are transparent and predictable. For savings, however, compound interest is better.