The formula
A vertical cylinder is the friendliest tank geometry there is: volume is exactly proportional to level, so every centimetre of level holds the same number of litres, and a level transmitter reading in % is also reading volume in %. This linearity is why vertical cylindrical tanks dominate storage duty.
Worked example
Diameter 2 m, liquid at 1.5 m:
- Footprint area: π × 1² = 3.1416 m²
- V = 3.1416 × 1.5 = 4.712 m³ = 4,712 litres
- Litres per cm: 3.1416 m² × 10 = 31.4 L/cm — the number to remember when someone asks "how fast are we filling?"
Field notes
- Use the internal diameter. Nameplate diameters are often external; on a large tank the wall thickness matters little, on a small vessel it doesn't.
- The linear relationship breaks at the ends: dished heads, cone bottoms and internal structures (heating coils, agitators) all displace or add volume. For custody transfer, only a certified strapping table counts.
- Level ≠ volume in horizontal tanks. If your tank lies on its side, the relationship is strongly nonlinear — use our horizontal tank calculator.
- Pairing with instrumentation: to range a DP transmitter for this tank, take the level span to our DP level calculator, and the height-to-pressure relation from the hydrostatic pressure tool.
Frequently asked questions
What is the formula for the volume of a vertical cylindrical tank?
V = π × (D/2)² × h, where D is the tank diameter and h the liquid level. Total capacity uses the full tank height H in place of h.
How many litres per centimetre of level does a tank hold?
The "litres per cm" is the tank footprint area: π(D/2)² × 10 litres per cm for D in metres. A 2 m diameter tank holds 31.4 litres per cm of level.
Does this work for tanks with dished or conical bottoms?
The cylinder formula covers the straight shell only. A dished or cone bottom adds volume below the cylindrical section — for accurate low-level readings you need the vendor strapping table or the head geometry.
Provided for reference and education. Verify independently before use in safety-critical work. See our disclaimer.