Simple Interest Calculator
Work out simple interest and the total amount from a principal, a yearly rate and a time in years, months or days.
Simple interest
Type the amount, the yearly rate and the time.
Interest
150.00
1,150.00
Total amount
3 years
Time in years
Private: Everything runs in this page. Nothing you type is sent anywhere or saved.
On this page
Simple interest examples
| Amount | Rate | Time | Interest | Total |
|---|---|---|---|---|
| 1000 | 5% | 3 years | 150.00 | 1,150.00 |
| 2500 | 3.2% | 2.5 years | 200.00 | 2,700.00 |
| 10000 | 6% | 18 months | 900.00 | 10,900.00 |
| 500 | 4% | 73 days | 4.00 | 504.00 |
| 1200 | 0% | 5 years | 0.00 | 1,200.00 |
Formula
interest = principal x rate x time (rate as a fraction, time in years); total = principal + interest
How the simple interest works
- Step oneType the amount and the yearly rate.
- Step twoType the time and choose the unit.
- Step threeRead the interest and the total amount.
What this tool does not do
- It does not compound the interest; see the compound interest calculator for that.
- It uses 365 days per year; banks may use another day count.
- It does not include fees, taxes or inflation.
Frequently asked questions
What is the difference from compound interest?
Simple interest is always worked out on the original amount. Compound interest is worked out on the amount plus the interest already earned, so it grows faster.
How are days turned into years?
Days are divided by 365. Banks may use 360 or the real number of days in a leap year, which changes the result slightly.
Does it work for loans?
Yes, for loans that charge simple interest. Most mortgages and car loans do not; use the loan payment calculator for those.