Simple interest calculator
With simple interest, interest is charged only on the original amount. This calculator gives the interest and the total for any period.
How to use this calculator
- Enter the principal.
- Enter the yearly interest rate.
- Enter the time and choose years, months or days.
- Read the interest and the total amount.
Worked examples
Example 1
₹1,00,000 at 9% for 3 years.
You enter
| Principal | ₹1,00,000 |
|---|---|
| Interest rate (per year) | 9% |
| Time | 3 |
| Time in | Years |
You get
| Simple interest | ₹27,000 |
|---|---|
| Total amount | ₹1,27,000 |
| Time in years | 3 |
Example 2
₹50,000 at 12% for 90 days.
You enter
| Principal | ₹50,000 |
|---|---|
| Interest rate (per year) | 12% |
| Time | 90 |
| Time in | Days |
You get
| Simple interest | ₹1,479 |
|---|---|
| Total amount | ₹51,479 |
| Time in years | 0.2466 |
How it works
Because interest is never added to the principal, it grows in a straight line. Some short-term loans and some bonds work this way; most savings and long loans compound instead.
Days are counted on a 365-day year, which is the common convention.
Formula
Simple interest = P x r x t, with r as a decimal and t in years.
Common questions
Simple or compound, which is better?
For a saver compound is better; for a borrower simple is cheaper.
How do I find the rate?
Rate = interest / (principal x time).
Does it include tax?
No.
Learn more
Read the lesson Money, inflation and interest on pusaram.com for the ideas behind this calculator.
Calculators give estimates for learning and planning. They are not financial, tax, legal or medical advice, and results depend entirely on the numbers you enter. Check rates, limits and rules with an official source or a qualified professional before acting.