Evaluate the variables of a circle with our circumference and area of a circle calculator.

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.

Free area and circumference of a circle math topic guide, including step-by-step examples, free practice questions, teaching tips and more!

See How to Calculate the Area below, but first the calculator: Enter the radius, diameter, circumference or area of a Circle to find the other three.

Jun 25, 2025 · Both area and perimeter can be calculated with simple formulas using the radius or diameter of the circle and the value of pi. Learn the formula for circumference.

Dec 1, 2025 · Because π is the ratio between the circumference and the diameter, the circumference of a circle is equal to the diameter times π. Area of a circle is the region occupied by the circle in a two …

Area and circumference are two important measures of a circle. The area tells us how much space is enclosed within a circle, while the circumference is the total distance around the edge of the circle.

Complete circle calculator: calculate radius, diameter, circumference, and area from any one known value. Free online circle calculator with formulas and step-by-step solutions.

Using the formula for the circumference of a circle, C = 2 π r, and substituting the radius (r = 7 cm), we get C = 2 × π × 7. This is a direct application of the formula, ensuring the radius is correctly used. …

Jul 23, 2025 · The formula for calculating a circle's circumference, or perimeter, is C = πd or C = 2πr, where "d" is the diameter and "r" is the radius. The formula A = πr2 represents the area of a circle, …