Tank Volume Calculator

Unit Conversion for Tank Volume

**Volume units**

- 1 m³ = 1000 L = 264.17 US gal = 219.97 imp gal

- 1 US gal = 3.785 L

- 1 bbl (oil) = 42 US gal = 0.159 m³

**Length units**

- 1 m = 3.28084 ft

- 1 inch = 25.4 mm

Tank volume V = π/4 × D² × L (cylindrical) requires consistent units. Convert diameter and length to the same unit before computing, then convert the result to the desired volume unit.

Tank Volume Formulas for Common Shapes

Three standard geometries cover most storage tanks:

Cylindrical (vertical or horizontal): V = pi/4 x D^2 x H, where D = diameter and H = height or length. A 3m x 6m cylinder holds 42.4 m3.

Rectangular: V = L x W x H. A 2m x 2m x 2m basin holds 8 m3 (8,000 L).

Spherical: V = pi/6 x D^3. A 3m sphere holds 14.14 m3 (14,137 L).

Convert volume to liters by multiplying m3 by 1000, and to US gallons by multiplying m3 by 264.17.

Worked Example: 3 m x 6 m Vertical Cylinder

A vertical cylindrical tank with D = 3 m and H = 6 m: radius = 1.5 m, so V = pi x 1.5^2 x 6 = 42.41 m3 = 42,412 L, or about 11,204 US gallons. This matches the calculator result. For the same tank laid horizontally with a partial liquid level, use the circular segment method: find the segment area from the fill height, then multiply by the tank length - the filled volume is not a linear fraction of the total volume.