Simple Interest Calculator
Finance
Calculate interest without compounding.
Formula
I = P × r × t
- Use the units shown beside each field.
- Results update automatically whenever you change an input.
- Displayed values use up to four decimal places, or scientific notation for very small or large numbers. Calculations retain full precision.
Example Calculation
Example inputs
- Principal: 5000 $
- Annual rate: 6 %
- Time: 3 years
$5,000 at 6% for 3 years earns $900.
Frequently asked questions
How do I use this calculator?
Enter principal, annual rate, time. The result updates automatically. Use Reset to restore the example values.
What method does it use?
I = P × r × t. Follow the units and definitions shown with the inputs to apply this relationship consistently.
Why might a rounded result differ?
The calculation keeps full numeric precision internally, then rounds the displayed result. Rounding intermediate steps by hand can produce a slightly different answer.
Are my inputs saved online?
No. This calculator processes your inputs in your browser. A recently used list stores only calculator names on this device, not your entered values.
Check the assumptions and units before using this result. Read about calculation methods.