Sphere Surface Area Calculator
Enter a sphere radius or diameter to calculate its total surface area instantly, with units preserved and no data leaving your browser.
A QUICK WALKTHROUGH
How to use this tool
- Choose whether your measurement is a radius or diameter.
- Enter a positive number and select Calculate surface area.
- Review the exact formula and rounded result with your chosen units.
Use the sphere surface area formula
The calculator applies A = 4πr². If you enter a diameter, it first divides the diameter by two to obtain the radius.
Keep your units consistent
Surface area uses square units. Enter a radius in meters for a result in square meters, or centimeters for square centimeters.
Calculation stays local
Validation and arithmetic run in your browser. Your measurement is not sent to a server.
GOOD TO KNOW
Common questions
What is the surface area formula for a sphere?
The formula is A = 4πr², where r is the sphere radius.
Can I enter a diameter instead?
Yes. Choose Diameter and the calculator converts it to a radius before applying the formula.
What units does the result use?
The result uses the square of the unit you enter, such as cm², m², or in².
Does this calculate volume too?
No. This page calculates surface area only. Sphere volume uses a separate formula, V = 4/3πr³.