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 …

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 …

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 …

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.

What is circumference anyway? Answer: The circumference of a circle is the edge or rim of a circle itself. It is the equivalent of 'perimeter' for a circle. The glowing part in the circle above is the …

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".

Dec 31, 2025 · Circumference is the length of the outer edge of a circle, and you can think of it like the circle’s perimeter, which helps you measure things like paint needed for a round tabletop.

The perimeter of a circle is called the circumference and is the linear distance around the edge of a circle. The circumference of a circle is proportional to its diameter, d, and its radius, r, and relates to …

The circumference of the circle is the length of its boundary. Explore and learn to calculate the circumference of a circle, with concepts, definitions, formulas, solved examples, and practice problems.