Circumference Calculator
From Radius
From Diameter
From Circumference
Formula
C = 2πr = πd
Frequently Asked Questions
What is circumference?
Circumference is the perimeter of a circle: C = 2πr = πd. For a circle with radius 7: C = 2 × 3.14159 × 7 ≈ 43.98.
You may also need
+
Area of Circle Calculator
Free circle calculator. Calculate area, circumference, and diameter of a circle from radius, diameter, or area.
Math+
Pythagorean Theorem Calculator
Free Pythagorean theorem calculator. Find the missing side of a right triangle. Calculate hypotenuse or leg length from two known sides.
Math+
Volume Calculator
Free volume calculator. Calculate volume of a box, cylinder, sphere, and cone. Convert between gallons, liters, and cubic feet.
Math