Sphere Surface Area Calculator

Calculate the surface area of a sphere by entering the radius. A sphere is a perfectly round 3D object.

⚪ Sphere Surface Area

Formula

Surface Area: SA = 4πr²
Where r is the radius of the sphere

Sphere Surface Area Formula

Surface Area

SA = 4πr²

The surface area is 4 times the area of a circle with the same radius

Volume

V = (4/3)πr³

Volume is four-thirds times π times radius cubed

Diameter

d = 2r

Diameter is twice the radius

Circumference

C = 2πr

Circumference of the great circle

Sphere Surface Area Examples

Example 1: Small Sphere

Given: Radius = 2 cm

Formula: SA = 4πr²

Solution: SA = 4π × 2² = 4π × 4 = 16π ≈ 50.27 cm²

Example 2: Medium Sphere

Given: Radius = 5 cm

Formula: SA = 4πr²

Solution: SA = 4π × 5² = 4π × 25 = 100π ≈ 314.16 cm²

Example 3: Large Sphere

Given: Radius = 10 cm

Formula: SA = 4πr²

Solution: SA = 4π × 10² = 4π × 100 = 400π ≈ 1256.64 cm²

Sphere Surface Area FAQ

What is a sphere?

A sphere is a perfectly round 3D object where every point on the surface is exactly the same distance (radius) from the center.

How do you calculate sphere surface area?

To find the surface area of a sphere, use the formula SA = 4πr², where r is the radius of the sphere.

Why is the sphere formula 4πr²?

The formula comes from calculus and integration. It's exactly 4 times the area of a circle with the same radius (πr²).

What's the difference between surface area and volume?

Surface area measures the total area of the outer surface (in square units), while volume measures the space inside (in cubic units).