How to use the simple interest calculator
- Principal: Starting amount on which interest is calculated.
- Annual rate (%): Annual simple interest rate.
- Years: Time in years; decimals are allowed.
- Select Calculate to see the result. Change any input and calculate again to compare.
Worked example
1,000 at 5% simple interest for 2 years earns 100.
Formula and assumptions
Interest = principal × rate × time.
No compounding, additional deposits, fees or taxes are included.
Common questions
Why might my result differ from another estimate?
No compounding, additional deposits, fees or taxes are included. Keep the same inputs and rounding when comparing tools.
Are my entries saved?
No. Calculations run on your device. Reloading or closing this page may clear your entries.