Sphere Surface Area Calculator – ProMathTools

Sphere Surface Area Calculator

Find the surface area of a sphere instantly by entering its radius. Perfect for geometry students and quick calculations.

Radius (r)

Enter the sphere's radius

How it works

Find the surface area of a sphere instantly by entering its radius. Perfect for geometry students and quick calculations.

The Formula

A = 4πr²
Where:
A = Surface Area
r = Radius
π ≈ 3.14159

Worked Example

Example: A Basketball's Surface
Imagine a basketball with a radius of 12 cm. Using the formula A = 4πr², its surface area would be 4 × π × (12 cm)² = 4 × π × 144 cm² ≈ 1809.56 cm².

Tips, Assumptions & Limitations

Ensure your radius measurement is accurate for precise results.
Remember that surface area is always expressed in square units (e.g., cm², m², in²).
The formula A = 4πr² is a fundamental concept in geometry.

FAQ

The formula is A = 4πr², where 'A' is the surface area and 'r' is the radius of the sphere.

Surface area measures the total area of the sphere's outer surface (like the skin of a ball), while volume measures the amount of space it occupies (like how much air is inside the ball). The volume formula is V = (4/3)πr³.

Yes, you can enter the radius in any unit (e.g., cm, inches, meters). The resulting surface area will be in the corresponding square units (e.g., cm², in², m²).