Geometry
Volume of a sphere
Cube the radius first, then multiply by pi and by four thirds. The cube is what makes volume grow so much faster than radius.
The Formula
V = (4/3) x pi x r^3
Cube the radius first, then multiply by pi and by four thirds. The cube is what makes volume grow so much faster than radius.
| Symbol | Meaning | Unit | Notes |
|---|---|---|---|
| V | Volume | cubic units | The space the sphere encloses. |
| r | Radius | linear units | Distance from the centre to the surface. |
| pi | Pi | dimensionless | 3.141592653589793, the ratio of circumference to diameter. |
What Each Symbol Means
Vcubic units
Volume
The space the sphere encloses.
rlinear units
Radius
Distance from the centre to the surface.
pidimensionless
Pi
3.141592653589793, the ratio of circumference to diameter.
See It Worked With Real Numbers
A formula on its own does not tell you which number goes where. The how to calculate the volume of a sphere page applies this equation to a concrete case, shows every intermediate step, and names the mistakes that produce a wrong answer even when the algebra is right.
Where This Formula Appears
This equation is the working core of How To Calculate The Volume Of A Sphere, filed under Math. Every number the guide produces comes from substituting into this one line.