The formula to calculate the area of a circle using radius is as follows: Area of a circle = π × r2. And, to calculate the area of a circle using diameter use the following equation: Area of a circle = π × (d/2)2. …

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.

Oct 29, 2025 · To find the area of a circle, use the formula A = π • r2, where r is the radius of the circle. If you only know the diameter of the circle, then use the formula A = π • (d/2)2 where d is diameter.

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. Units: …

Oct 25, 2023 · The area of a circle can be calculated using three different formulas. The formulas are used based on whether the radius, diameter, or circumference is known to us.

Using A = πr2, The formula for the area of a circle can be proven in a number of ways. One such way involves breaking the circle into equal sectors and rearranging them to construct a parallelogram. In …

Square the radius and multiply by π. The most common method for finding area. Square the diameter, multiply by π, then divide by 4. Square the circumference and divide by 4π. The area of a circle …

Apr 29, 2025 · Learn how to calculate the area of a circle with step-by-step examples. Includes formulas, derivation, practical applications, and practice problems...

Alternatively, the space occupied within the boundary/circumference of a circle is called the area of the circle. The formula for the area of a circle is A = πr 2, where r is the radius of the circle. The unit of …

Jun 9, 2025 · Learn how to find the area of a circle with clear formulas, step-by-step examples, and visual explanations—perfect for students and math learners of all levels.