Simple Interest Calculator: Calculate Interest Earned
Calculate simple interest from principal, rate, and time with this easy financial calculator.
Simple Interest Calculator
Simple interest is one of the most fundamental concepts in finance. Whether you're looking at a savings account, a loan, or an investment, understanding simple interest helps you make better financial decisions. It's the starting point for all interest calculations.
The Simple Interest Formula
Interest = Principal × Rate × Time
Where:
- Principal: The initial amount of money
- Rate: Annual interest rate (as a percentage)
- Time: Duration in years
For example, investing $10,000 at 5% annual interest for 3 years earns $1,500 in simple interest.
Simple vs. Compound Interest
The key difference is that simple interest is calculated only on the principal amount, while compound interest is calculated on both the principal and accumulated interest. Over short periods, the difference is minimal. Over longer periods, compound interest grows significantly faster.
When Simple Interest is Used
Short-term Loans: Some personal loans and car loans use simple interest calculations.
Treasury Bills: Government securities often use simple interest.
Certain Bonds: Some bond types pay simple interest.
Limitations
Simple interest doesn't account for the effect of compounding, which is why most real-world financial products use compound interest. However, understanding simple interest is essential for comparing financial products and making informed investment decisions.
Always check whether an interest rate is simple or compound when evaluating financial products—the difference can be substantial over time.