⭕ Area of Circle Calculator

Circle Measurements

Circle Area Formula

A circle is a perfectly round shape where all points are equidistant from the center. The key measurements are radius, diameter, area, and circumference.

Area = π × r² (where π ≈ 3.14159)
Circumference = 2 × π × r = π × d
Diameter = 2 × radius

Circle Calculation Examples

r = 5 cm
Area = 78.54 cm²
r = 10 m
Area = 314.16 m²
d = 14 cm
Area = 153.94 cm²
r = 7 in
C = 43.98 in

Frequently Asked Questions

What is the area of a circle with radius 5? ▼
Area = π × 5² = π × 25 ≈ 78.54 square units. Using π = 3.14159.
How do you find the area from the circumference? ▼
From C = 2πr, get r = C/(2π). Then Area = πr². For C = 31.4: r = 31.4/(2π) ≈ 5, Area = π×25 ≈ 78.54.
What is the difference between area and circumference? ▼
Area measures the space inside the circle (in square units). Circumference is the perimeter/distance around the circle (in linear units).