Simple Interest Calculator
Calculate the basic interest earned on a principal amount over a fixed period of time. Perfect for personal loans, simple savings, and everyday math.
Example Calculation
See how interest is calculated on a $10,000 principal over 5 years at an annual rate of 6%.
The Formula
Simple Interest (SI) = (P × R × T) / 100
Step 1: Multiply Principal, Rate, and Time
10,000 × 6 × 5 = 300,000
Step 2: Divide by 100
300,000 / 100 = $3,000
Interest: $3,000
Total Amount: $13,000
Frequently Asked Questions
What is simple interest?
Simple interest is a quick and easy method of calculating the interest charge on a loan or investment. It is determined by multiplying the daily interest rate by the principal by the number of days that elapse between payments.
How is it different from compound interest?
Simple interest is calculated only on the principal amount of a loan. Compound interest is calculated on the principal amount and also on the accumulated interest of previous periods, which makes it grow faster over time.
When is simple interest used in real life?
Simple interest is commonly used for short-term loans, automobile loans, and personal loans between individuals. Some certificates of deposit (CDs) also pay simple interest rather than compounding it.
Is simple interest better or worse for borrowers?
Generally, simple interest is better for borrowers because they only pay interest on the original amount borrowed. For lenders and investors, compound interest is usually preferred as it generates higher returns over the same period.
How do I calculate simple interest manually?
The manual formula is Interest = Principal × Rate × Time. For example, if you borrow $1,000 at 5% for 2 years, the math is 1000 × 0.05 × 2 = $100 in interest.
What is the difference between interest rate and APR?
The interest rate is the cost of borrowing the principal amount. The Annual Percentage Rate (APR) is a broader measure that includes the interest rate plus any other fees or costs required to get the loan, expressed as a percentage.
This calculator provides estimates for informational purposes only. Actual financial outcomes depend on specific contract terms and banking practices. Consult a qualified professional before making financial decisions.