How it works
Volume = 4/3 × π × radius³radius cubed, so small changes matter a lot
- radius
- from the centre to the surface
- π
- pi, about 3.14159
- radius³
- the radius multiplied by itself three times
Use the radius, not the diameter. If you know the diameter, halve it: a ball 10 cm across has a 5 cm radius.
Frequently asked questions
What is the volume of a sphere with radius 5?
About 523.6 cubic units.
What is the formula for the volume of a sphere?
Four-thirds pi times the radius cubed, 4/3 π r³.
What happens if I double the radius?
The volume grows eight times, because the radius is cubed.
How do I find it from the diameter?
Halve the diameter to get the radius, then use 4/3 π r³.