Simple Interest Calculator — online
Calculate simple interest, total amount and earnings.
Formula: SI = (P × R × T) / 100
Where P = Principal, R = Rate per annum, T = Time in years
How to use Simple Interest Calculator
Enter Your Principal Amount
Click the 'Principal Amount' input field at the top of the calculator and type your initial investment or loan amount in dollars. For example, enter 5000 for $5,000.
Input the Annual Interest Rate
Click the 'Annual Interest Rate (%)' field and enter your percentage rate. Type the number without the % symbol—for example, enter 5 for a 5% annual rate.
Set the Time Period
Click the 'Time (Years)' field and enter how many years the interest will accrue. Enter whole numbers or decimals—for example, enter 2.5 for 2.5 years.
View Your Results Instantly
The calculator automatically displays your Simple Interest Earned, Total Amount (principal + interest), and a breakdown table. Results update in real-time as you adjust any field.
Copy or Clear Your Calculation
Click the 'Copy Results' button to copy all calculations to your clipboard, or click 'Clear' to reset all fields and start a new calculation.