Gallons To Cubic Feet
Convert US gallons (gal) to cubic feet (cu ft) instantly with this free online volume converter. Supports both US and UK gallons with accurate formulas.
About This Calculator
The Gallons to Cubic Feet Converter is a free online tool that instantly converts volume between gallons (both US liquid and UK imperial) and cubic feet (cu ft or ft³). Whether you are an aquarium hobbyist sizing a tank, a contractor calculating concrete volume, a shipper estimating freight space, or a homeowner measuring fuel storage, this converter provides accurate results in seconds.
How it works: The conversion uses standard volume formulas. One US liquid gallon equals exactly 231 cubic inches, which translates to 0.133681 cubic feet. One UK imperial gallon (used in the United Kingdom and Commonwealth countries) is larger at 4.546 liters, equal to 0.160544 cubic feet. The calculator multiplies your input by the appropriate conversion factor based on the selected gallon type.
Regional Notes
United States: US liquid gallons are the standard unit for fluid volume in everyday use, including gasoline, milk, water, and other liquids. Converting to cubic feet is common for large-volume applications like swimming pools, water tanks, and industrial storage.
United Kingdom: UK imperial gallons are used for fuel economy (miles per gallon) and beer/ale measurements. Note that UK gallons are approximately 20% larger than US gallons, so always specify which gallon type you are using.
Other regions: Most countries use the metric system (liters) for volume. This converter helps bridge the gap between imperial/customary units and cubic feet, which is still widely used for construction, HVAC, shipping, and engineering in the US and UK.
Applications: Common use cases include aquarium volume calculation (fish tanks are often sold by gallon but measured in cubic feet for filtration sizing), freight shipping (dimensional weight), pool chemical dosing, water heater sizing, and propane tank capacity estimation.
Frequently Asked Questions
How do you convert gallons to cubic feet?
To convert gallons to cubic feet, multiply the number of gallons by 0.133681 for US gallons or by 0.160544 for UK gallons. For example, 10 US gallons equals 1.33681 cubic feet, while 10 UK gallons equals 1.60544 cubic feet.
What is the difference between US and UK gallons?
A US liquid gallon equals 3.785 liters or 231 cubic inches, while a UK imperial gallon equals 4.546 liters. UK gallons are about 20% larger than US gallons. When converting to cubic feet, 1 US gal = 0.133681 ft³ and 1 UK gal = 0.160544 ft³.
How many cubic feet are in 5 gallons?
There are 0.6684 cubic feet in 5 US gallons and 0.8027 cubic feet in 5 UK gallons. Simply multiply 5 by 0.133681 for US or 0.160544 for UK.
How many gallons are in a cubic foot?
There are approximately 7.4805 US gallons or 6.2288 UK gallons in 1 cubic foot. To convert cubic feet back to gallons, divide the cubic foot value by 0.133681 for US gallons or by 0.160544 for UK gallons.
Is this gallons to cubic feet converter free?
Yes, this gallons to cubic feet converter is completely free to use with no registration required. You can make unlimited conversions between US gallons, UK gallons, and cubic feet.
When would I need to convert gallons to cubic feet?
Converting gallons to cubic feet is useful for aquarium tank sizing, shipping container volume calculations, fuel storage, swimming pool measurements, water tank capacity, and construction projects that require volume conversions between US customary and imperial units.
What is the formula for gallons to cubic feet?
The formula is: Cubic Feet = Gallons x Conversion Factor. For US gallons, use 0.133681 as the conversion factor. For UK gallons, use 0.160544. A cubic foot is defined as a cube with 1-foot sides, containing 7.4805 US gallons or 6.2288 UK gallons.
Can I convert cubic feet back to gallons using this calculator?
This tool is designed for gallons to cubic feet conversion. To convert cubic feet back to gallons, divide the cubic feet value by 0.133681 for US gallons or by 0.160544 for UK gallons.