Formula
\(A = \frac{\pi D^2}{4} \qquad V = A\,H \qquad V_L = A\,L \qquad f = \frac{L}{H}\)
Variables
| Symbol | Meaning | SI unit |
|---|---|---|
| \(D\) | inside diameter of the shell | m |
| \(H\) | height of the cylindrical shell | m |
| \(L\) | liquid level above the bottom | m |
| \(A\) | cross-section area | m² |
| \(V\) | total shell volume | m³ |
| \(V_L\) | volume below the liquid level | m³ |
| \(f\) | fill fraction | – |
Method and standards
Plain geometry of a right circular cylinder. Enter the inside diameter (outside diameter minus twice the wall thickness) for the liquid capacity.
Assumptions and limits
- Vertical axis, flat bottom, no heads, no internals.
- A level above the shell height is treated as full and flagged.
References
- Geometry of a right circular cylinder
Questions and answers
Does the calculator include dished or conical heads?
No. It treats the tank as a plain cylinder. Add the head volumes separately; for a 2:1 ellipsoidal head the volume is πD³/24 per head.
Why is the filled volume proportional to the level?
In a vertical cylinder every horizontal slice has the same area, so volume rises linearly with level. A horizontal cylinder does not behave this way.