Circumference Calculator

Your details

Enter the radius of the circle. Switch "Solve from" to enter a different known measurement.
cm
Add a central angle to find the arc length and sector area for that slice of the circle.
Circumference
31.4159cm
Area78.5398cm²
Radius5cm
Diameter10cm

A circle with radius 5 cm has a circumference of 31.416 cm.

  • Circumference grows in direct proportion to the radius: double the radius and you double the distance around the circle.
  • The enclosed area is 78.54 square cm, which scales with the square of the radius.
  • The ratio of circumference to diameter is always pi (about 3.14159), no matter how large or small the circle.

Next stepSwitch "Solve from" to enter a diameter, circumference, or area instead, or toggle on arc and sector to find a slice of the circle.

 = Powered by OnlyCalculators