r = radius
V = volume
A = surface area
C = circumference
π = pi = 3.14159
√ = square root
This online calculator will calculate the 3 unknown values of a sphere given any 1 known variable including radius r, surface area A, volume V and circumference C. A sphere is a set of points in three dimensional space that are located at an equal distance r (the radius) from a given point (the center point).
* Units: Note that units are shown for convenience but do not affect the calculations. The units are in place to give an indication of the order of the results such as ft, ft2 or ft3. For example, if you are starting with mm and you know a and r in mm, your calculations will result with S in mm2, V in mm3 and C in mm.
Use the following additional formulas along with the formulas above.