FINANCE · FREE TOOL
Simple interest calculator
Calculate noncompounding interest from principal, rate and decimal years.
Your inputs
Enter your values, then calculate.
Decimal-point numbers; displayed rounding does not change internal values. Calculations stay on this device.
YOUR RESULT
Make the numbers clear.
Save calculation JSON ↓Calculation breakdown
Scroll sideways to see every column. You can also focus the table and use the arrow keys.
How this calculation works
I = P × annual rate × years. This is simple interest, without recurring deposits or compounding. For a day-based contract, first convert its days using the contract’s actual day-count basis; this tool does not infer that basis.
Check the assumptions
Use one currency consistently; financial outputs use that same currency, except the U.S. tax tool specifically uses USD. Financial models use your assumptions, not live rates or personalized financial advice. Check the result against your contract or the applicable tax rules.