Interest Calculator
Calculate simple interest and the total amount owed or earned using principal, annual rate, and time in years.
How it works
- 1
Enter your values in the fields.
- 2
Results update automatically as you type.
- 3
Use Reset to clear and try another scenario.
Why use this calculator
- Simple interest formula
- Clear total amount
- Fast comparisons
- No account needed
Simple vs compound interest
Simple interest grows only on the original principal. Use this tool for quick estimates; use the compound interest calculator for reinvested growth.
Formula used
Interest = principal × rate × time. FlyCalculator also shows principal plus interest as the total.
Frequently asked questions
Is this compound interest?
No. This page uses simple interest only.
Can rate be monthly?
Enter an annual rate percentage. Convert monthly rates to annual before using the tool.
What is total?
Principal plus calculated interest.