How do you find the radius and diameter of a circle? To calculate the radius of a circle, divide its circumference by 2π; for the circle's diameter, divide the circumference by π.

Jul 23, 2025 · To calculate the diameter of a circle we use the formula D = 2r. The diameter of any circle is the longest chord of the circle, that passes through the centre of the circle.

Aug 1, 2025 · Use this circle calculator to find the area, circumference, radius or diameter of a circle. Given any one variable A, C, r or d of a circle you can calculate the other three unknowns.

The diameter of a circle is any straight line segment that passes through the center of the circle and whose endpoints lie on the circumference of the circle. The diameter is also known as the longest …

Apr 15, 2025 · You can also find the diameter of a circle if you know its circumference, or the distance all the way around the outside of the circle. Just divide the circumference by π to find the diameter.

The diameter of a circle is the length of the line through the center and touching two points on its edge. In the figure above, drag the orange dots around and see that the diameter never changes.

Jun 1, 2025 · Instantly calculate circle diameter, radius, area, and circumference from various inputs. Ideal for geometry, engineering, construction, and educational use.

Online circle of diameter calculation. Use this simple geometry circle of diameter calculator to calculate diameter of circle.

Nov 14, 2025 · Quickly calculate radius, diameter, circumference, and area of a circle. Use this Circle Calculator for math, engineering, or design projects online.

Three diameters are drawn for circle O below. As long as the line segment passes through the center and has its endpoints on the circle, it is a diameter. The diameter of a circle is twice the length of the …