Calculate simple interest
Simple Interest = Principal × Rate × Time (I = P × r × t). Unlike compound interest, simple interest is calculated only on the original principal amount. Total Amount = Principal + Interest. This linear growth pattern is common in short-term loans and bonds.
Simple interest is used for many auto loans, short-term personal loans, and some savings bonds. Understanding the difference between simple and compound interest helps you compare financial products and choose the best option.
Simple interest grows linearly - $10,000 at 5% earns $500 per year always. Compound interest grows exponentially as interest earns interest. Over long periods, compound interest significantly outperforms simple interest.
For borrowers: Simple interest loans are often better since interest doesn't compound. For savers: Seek compound interest investments for long-term growth. Always verify which type of interest applies before signing any financial agreement.
Simple interest is calculated only on the original principal amount and grows linearly over time. Compound interest is calculated on the principal plus all previously accumulated interest, causing exponential growth. For example, $10,000 at 5% simple interest earns $500 every year. With compound interest, year one earns $500, year two earns $525 (5% of $10,500), and so on. Over 20 years, simple interest yields $20,000 while compound interest yields $26,533.
Simple interest is commonly used for auto loans, short-term personal loans, some certificates of deposit, Treasury bills, and consumer installment loans. It is also used in some student loans for calculating daily interest charges. Lenders prefer simple interest for short-term lending because it is straightforward to calculate. Borrowers benefit from simple interest loans since the interest does not compound, resulting in lower total interest costs.
Simple interest is calculated using the formula I = P × r × t, where I is the interest amount, P is the principal (initial amount), r is the annual interest rate (as a decimal), and t is the time in years. For example, to find the interest on a $5,000 loan at 6% for 3 years: I = $5,000 × 0.06 × 3 = $900. The total amount owed would be $5,000 + $900 = $5,900.