Circumference Calculator
Calculate the circumference, diameter, radius, or area of a circle given any one value.
Published by:
isCalculator Editorial Team
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How to use this tool?
How to use the Circumference Calculator:
- Enter a known value in the "Known Value" field (e.g., 10). Use any positive number; units are generic (metric or imperial work the same).
- Select the known dimension from the dropdown: Radius, Diameter, Circumference, or Area.
- Click "Calculate" to compute all missing values.
- View results below: Radius, Diameter, Circumference (highlighted in green), and Area. The formula used is also shown.
Tip: If you enter a non-positive number, an error will appear. Clear the input or enter a positive value to proceed.
Previous Results
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Frequently Asked Questions
Circumference is calculated using the formula C = 2πr, where r is the radius, or C = πd, where d is the diameter.
Yes, you can enter the circumference and the calculator will compute the radius and then the area using A = πr².
The calculator works with any consistent units (e.g., inches, cm, feet). The result will be in the same unit squared for area.
