Click save settings to reload page with unique web page address for bookmarking and sharing the current tool settings, or click flip tool to reverse the tool function with current settings

Switch tool with the current settings for radius, and calculate sphere volume, circle area, circle circumference or diameter instead

## Related Tools

- Calculate surface area of sphere from radius
- Sphere volume to radius calculator
- Convert an area to different units
- Length and distance converter
- Circle area to radius calculator
- Circle circumference to radius calculator
- Circle diameter to radius calculator

## User Guide

This tool will calculate the radius of a sphere from the surface area, and will convert different measurement units for surface area and radius.

#### Formula

The formula used to calculate the sphere radius is:

r = √(A / (4 · π))

###### Symbols

- r = Sphere radius
- A = Sphere surface area
- π = Pi = 3.14159…

#### Surface Area of Sphere

Enter the surface area of a sphere. The sphere surface area represents the total area of the outer surface of the sphere if it was to be laid out flat as a two-dimensional shape, e.g. a true scale map of the world is a 2D scaled representation of the surface area of the world.

#### Radius of Sphere

This is the radius of the sphere which corresponds to the volume specified. The radius is the distance between the centre and any point on the surface of a sphere.