Simple Interest Calculator
Quickly estimate interest earned on your principal at a fixed rate
How to use ?
Add Some
Currency
Interest rate
Time period or end date
Start date / end date
Regular contributions
Some Calculate
Click the calculate Button
Some Result
Simple interest projection :
Final balance
Initial balance
Interest accrued
Monthly interest
Monthly / yearly Breakdown
Why Use?
Why Use This Simple Interest Calculator?
What is Simple Interest?
Simple interest is a straightforward method of calculating interest only on the original amount you deposited or borrowed — not on any previously earned interest. It is commonly used for personal loans, vehicle loans, education loans, and fixed deposits.
How is Simple Interest Calculated?
The basic calculation is: I = P × r × t Where I is the interest earned, P is your starting amount, r is the annual rate as a decimal, and t is the number of years.
To find the total amount including your original deposit: A = P(1 + rt)
Example : You invest ₹5,000 at 5% per year for 4 years. A = 5000 × (1 + 0.05 × 4) = ₹6,000 Total interest earned = ₹1,000, which is ₹250 every year.
| Year | Principal | Total Interest | Total |
|---|---|---|---|
| 1 | $5,000 | $250 | $5,250 |
| 2 | $5,000 | $500 | $5,500 |
| 3 | $5,000 | $750 | $5,750 |
| 4 | $5,000 | $1,000 | $6,000 |
Other Useful Formulas
Calculate Principal: P = A / (1 + rt)
Calculate Interest Rate: R = (1/t)(A/P - 1) × 100
Calculate Time Period: t = (1/r)(A/P - 1)
Simple vs Compound Interest
Simple interest is calculated only on the principal every time — making it more advantageous for borrowers but less beneficial for savers.
Compound interest, on the other hand, earns interest on already accumulated interest, making it far more powerful for long-term savings growth.
How to Use This Calculator
Enter your opening balance and annual interest rate, then set how long you want to calculate for. Add any regular contributions if needed, hit Calculate, and instantly get your total interest, final balance, and a complete period-by-period breakdown.