Use this free circumference calculator to find the area, circumference and diameter of a circle.

In geometry, the circumference (from Latin circumferēns 'carrying around, circling') is the perimeter of a circle or ellipse. The circumference is the arc length of the circle, as if it were opened up and …

Aug 3, 2023 · The circumference of a circle is the distance around the boundary of the circle. It is the same as calculating the perimeter of any polygon such as triangle, square, and rectangle.

Use this calculator to easily calculate the circumference of a circle, given its radius in any metric: mm, cm, meters, km, inches, feet, yards, miles, etc. If you know the diameter, first divide it by two to get …

Oct 7, 2025 · Keep reading for everything you need to know about how to figure out the circumference of a circle using either the diameter or the radius. We've even got a circumference calculator to make …

This calculator computes the values of typical circle parameters such as radius, diameter, circumference, and area, using various common units of measurement.

Jul 23, 2025 · The circumference of a circle is equal to the length of its boundary, but the circle is a curved shape, its circumference can't be measured with a ruler. The correct way to find the perimeter …

The formula for circumference is based on the constant π (pi), which is an irrational number approximately equal to 3.14159. π is the ratio of the circumference to the diameter of any circle.

Dec 1, 2025 · In the work, the term "circumference" is used to mean the perimeter of a circle. However, some authors allow "circumference" to refer more generally to the distance or arc length around an …

You sometimes see the word 'circumference' to mean the curved line that goes around the circle. Other times it means the length of that line, as in "the circumference is 2.11cm".