Calculate the volume of a cylinder in US gallons, imperial gallons, liters, and cubic feet. Enter radius or diameter and height in any unit with adjustable fill level.
The Cylinder Volume in Gallons Calculator computes the capacity of any cylindrical container — tanks, barrels, pools, pipes, and more — and expresses the result in US gallons, imperial gallons, liters, cubic feet, and several other volume units. This is the go-to tool whenever you need to know how many gallons a round container holds.
Whether you are filling a swimming pool, sizing a water storage tank, estimating how much fuel fits in a cylindrical tank, or planning a rain barrel installation, knowing the volume in gallons is essential. While the mathematical formula V = πr²h is simple, converting the result from cubic centimeters or cubic inches into gallons requires careful unit handling — and that is exactly what this calculator automates.
You can enter measurements in centimeters, millimeters, meters, inches, feet, or yards with the calculator handling all conversions internally. Choose between entering the radius or the diameter. An adjustable fill-level slider lets you calculate partial volumes — perfect for knowing how many gallons are in a half-full tank.
Eight presets cover common containers from 1-gallon paint cans to 300-gallon hot tubs. The conversion reference table provides quick US-to-imperial gallon and liter equivalents. Visual bars compare the different volume units so you can quickly gauge scale.
The Cylinder Volume in Gallons Calculator is useful when you need fast and consistent geometry results without reworking the same algebra repeatedly. It helps you move from raw measurements to US Gallons, Imperial Gallons, Liters in one pass, with conversions and derived values shown together.
Use it to validate homework steps, check CAD or fabrication dimensions, estimate material requirements, and sanity-check hand calculations before submitting work.
Volume = πr²h. Convert to gallons: US gallons = Volume(cm³) / 3,785.41; Imperial gallons = Volume(cm³) / 4,546.09.
Result: 59.71 US gallons
A standard 55-gallon drum with radius 28.6 cm and height 88 cm has a volume of π × 28.6² × 88 = 226,125 cm³ ≈ 59.71 US gallons (actual capacity is slightly above the nominal 55-gallon rating).
This calculator combines the core geometry formula with the input mode selected in the interface, then derives companion values shown in the output cards, comparison bars, and reference tables. Use it to cross-check both direct calculations and reverse-solving scenarios where one measurement is unknown.
Cylinder Volume in Gallons Calculator calculations show up in coursework, drafting, construction layout, packaging, tank sizing, machining, and quality control. Instead of solving each transformation manually, you can test scenarios quickly and verify whether your dimensions remain within tolerance.
Pay close attention to unit systems: US gallons, imperial gallons, liters, and cubic units are not interchangeable, so conversion context matters. For best results, measure carefully, round only at the final step, and compare at least one manual calculation with the calculator output when building confidence.
Calculate the volume in cubic inches (π × r² × h) and divide by 231 to get US gallons, or use this calculator with any unit for automatic conversion. Use this as a practical reminder before finalizing the result.
A US gallon is 3,785.41 mL (231 in³), while an imperial gallon is 4,546.09 mL. An imperial gallon is about 20% larger than a US gallon.
For a vertical cylinder, multiply the full volume by the fill fraction. This calculator has a fill-level percentage input for exactly this purpose.
This calculator assumes the cylinder is upright. Horizontal cylinder partial-fill calculations are more complex and involve a different formula based on the liquid height inside the tank.
Multiply cubic feet by 7.48052 to get US gallons, or by 6.22884 for imperial gallons.
Radius = 6 ft, height = 4 ft. Volume = π × 6² × 4 = 452.39 ft³ ≈ 3,384 US gallons.