Circumference Calculator
Enter a circle's radius, diameter, or area to find its circumference — and the full circle profile.
Circumference Calculator
Our Circumference Calculator finds a circle's circumference from whichever measurement you already have — radius, diameter, or area — and fills in the rest of the circle's profile automatically.
What Is Circumference?
The circumference of a circle is the total distance around its edge — essentially its perimeter. It depends only on the circle's radius or diameter and the constant π (approximately 3.1416).
Circumference Formulas
From Diameter: C = πd
From Area: C = 2√(πA)
Example Calculations
From Radius: r = 6
C = 2 × π × 6 ≈ 37.70
✓ Circumference ≈ 37.70, Diameter = 12, Area ≈ 113.10
From Diameter: d = 12
C = π × 12 ≈ 37.70
✓ Circumference ≈ 37.70, Radius = 6, Area ≈ 113.10
From Area: A = 113.10
C = 2√(π × 113.10) ≈ 37.70
✓ Circumference ≈ 37.70, Radius ≈ 6, Diameter ≈ 12
Features of Our Circumference Calculator
Who Can Use This Calculator?
👉 Try our Circumference Calculator to get a circle's full measurements from just one known value.