About This Calculator
This calculator computes the circumference and area of a circle based on the radius or diameter you provide. You can also specify the value of π for the calculation, or use the default value (3.14159) if not provided.
How It Works
The calculator uses the following formulas:
Circumference = 2 × π × r
Area = π × r²
Where ris the radius of the circle.
Frequently Asked Questions
What if I only know the diameter?
The calculator will automatically compute the radius as half of the diameter and then calculate the circumference and area.
When should I use a custom value for π?
Custom π values are useful for school exercises or exams where π is specified as 3.14 or other simplified values. For precise results, leaving it blank uses 3.14159 by default.