Cylinder Volume in Gallons

Cylinder Volume in Gallons is a calculator designed to convert the volume of any cylinder directly into gallons — the standard volume unit used in the United States for fuel, water, and industrial liquids. This tool exists because gallons are not a metric unit, so converting from cubic measurements requires specific conversion factors that differ between US and Imperial systems.

This calculator is essential for anyone working with cylindrical tanks, drums, water heaters, or fuel storage in the US. It handles both US gallons (3.785 litres) and Imperial gallons (4.546 litres), so you get accurate results regardless of which standard you need.

Whether you're a pool owner calculating chemical dosing, a brewer sizing a fermenter, or an engineer specifying tank capacity, this tool eliminates the conversion hassle and gives you gallon measurements instantly.

Calculate volume in cubic inches using V = π × r² × h (with inches). Then divide by 231 for US gallons, or divide by 277.42 for Imperial gallons.

Alternatively, calculate in cm³ first, then divide by 3,785.41 (US) or 4,546.09 (Imperial).

Example: A cylindrical drum with radius 11.5 inches and height 33.5 inches has V = π × 132.25 × 33.5 = 13,917.9 in³. That's 60.25 US gallons.

Gallon measurements are standard for fuel tanks, water heaters, swimming pools, and brewing equipment in the US. A typical home water heater is a 40- or 50-gallon cylinder. A standard oil drum holds 55 US gallons.

For pool owners, knowing the gallon capacity determines chemical dosing. For brewers, fermenter size in gallons dictates batch size. Fuel tank capacity in gallons affects vehicle range and refueling planning.