Geometry
Volume from the diameter
Equivalent to halving the diameter first. Use it when the measurement you hold was taken across the object.
The Formula
V = pi x d^2 x h / 4
Equivalent to halving the diameter first. Use it when the measurement you hold was taken across the object.
| Symbol | Meaning | Unit | Notes |
|---|---|---|---|
| d | Diameter of the base | length | Twice the radius. This is the figure usually printed on packaging. |
| h | Perpendicular height | length | Unchanged from the standard form; it is never squared. |
| V | Volume enclosed | cubic units | Identical to the radius form, provided d is genuinely the diameter. |
What Each Symbol Means
dlength
Diameter of the base
Twice the radius. This is the figure usually printed on packaging.
hlength
Perpendicular height
Unchanged from the standard form; it is never squared.
Vcubic units
Volume enclosed
Identical to the radius form, provided d is genuinely the 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 cylinder 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 Cylinder, filed under Math. Every number the guide produces comes from substituting into this one line.