Step-by-step instructions
- Enter or select Radius.
- Tap Calculate.
- Review the result shown directly below the calculator.
Calculate circle area and circumference.
Calculate circle area and circumference.
Circle area uses πr² and circumference uses 2πr.
Enter a realistic value for Radius and tap Calculate to see the computed result.
Use the result as an estimate based on the values you entered. For planning decisions, double-check that the input units and assumptions match your real situation.
Tip: Keep all values in compatible units and use values from the same time period when the calculator compares two amounts.