Finance Calculators
Simple Interest Calculator
Calculate simple interest and the total amount from principal, rate and time.
Free foreverRuns in your browserNo sign-up
Simple interest
$1,800.00
$1,800.00
Interest
$11,800.00
Total amount
Simple interest uses SI = P x R x T / 100. Interest is charged only on the original principal, so it does not compound over time.
About the Simple Interest Calculator
The Simple Interest Calculator finds the interest charged on a principal using SI = P x R x T / 100, along with the total amount owed or earned.
Simple interest is calculated only on the original principal, so it does not compound. This makes it common for short-term loans and some fixed deposits.
You can enter the time in years or months, and every calculation runs entirely in your browser.
Key features
- Simple interest and total amount
- Time in years or months
- Locale-aware currency formatting
- Instant browser-based calculation
How to use
- 1Enter the principal and choose a currency.
- 2Enter the annual interest rate.
- 3Enter the time and choose years or months.
- 4Read the simple interest and total amount.
Frequently asked questions
- How is simple interest calculated?
- It uses SI = P x R x T / 100, where P is the principal, R is the annual rate and T is the time in years.
- How is it different from compound interest?
- Simple interest is charged only on the original principal, while compound interest is charged on the principal plus previously accrued interest.
- Can I use months for the time?
- Yes. Choose months and the calculator converts the period to years before applying the formula.