Lower secondary
Circle area and circumference
Circle area and circumference: formula, units and explained result. No account required. Processing stays in your browser.
A = πr²; P = 2πr
Area in m² and circumference in m.
How to use this calculator
- Identify the quantities and convert them to the units shown.
- Apply the formula first, then compare with the substitution and result.
- Check the assumptions and whether the order of magnitude makes sense.
Levels are approximate topic groupings, not a complete curriculum for every country. Numerical results are rounded and may lose precision for extreme or nearly singular inputs.
A practical example
Use these sample inputs to check the calculation before entering your own values.
- Radius (m)
- 3
Result for this example
- Area
- 28.274333882308138 m²
- Circumference
- 18.84955592153876 m