Convert Imperial Gallons to Cubic Feet
1 imperial gallon (gal (imp)) equals 0.1605436532 cubic feet (ft³).
1 gal (imp) = 0.1605436532 ft³
Type in either box. Scientific notation works: 1.5e-3.
Converting a list? Use the bulk imperial gallon to cubic foot converter to paste a column from Excel.
How to Convert Imperial Gallon to Cubic Foot
- 1 gal (imp) = 0.1605436532 ft³
- 1 ft³ = 6.228835459 gal (imp)
- Example: convert 15 gal (imp) to ft³: 15 gal (imp) = 15 × 0.1605436532 ft³ = 2.408154799 ft³
Formula
ft³ = gal (imp) × 0.1605436532359
or ft³ = gal (imp) ÷ 6.228835459043
Derivation from SI units:
- 1 imp gal = 4.54609 L = 0.00454609 m³ (exact, by definition)
- 1 ft³ = (0.3048 m)³ = 0.028316846592 m³
- 1 gal (imp) = 0.00454609 m³ ÷ 0.028316846592 m³ per ft³ = 0.1605436532359 ft³
Both units are defined exactly, so the factor is exact. Imperial Gallon definition: imperial gallon; Cubic Foot definition: cubic foot.
Worked examples
- A reading of 5 gal (imp) converts to 0.8027182662 ft³.
5 gal (imp) × 0.1605436532 = 0.8027182662 ft³ - A value of 25 gal (imp) is 4.013591331 ft³.
25 gal (imp) × 0.1605436532 = 4.013591331 ft³
Imperial Gallon to Cubic Foot conversion table
| Imperial Gallons (gal (imp)) | Cubic Feet (ft³) |
|---|---|
| 0.25 gal (imp) | 0.04013591331 ft³ |
| 0.5 gal (imp) | 0.08027182662 ft³ |
| 1 gal (imp) | 0.1605436532 ft³ |
| 2 gal (imp) | 0.3210873065 ft³ |
| 5 gal (imp) | 0.8027182662 ft³ |
| 10 gal (imp) | 1.605436532 ft³ |
| 15 gal (imp) | 2.408154799 ft³ |
| 20 gal (imp) | 3.210873065 ft³ |
| 25 gal (imp) | 4.013591331 ft³ |
| 40 gal (imp) | 6.421746129 ft³ |
| 50 gal (imp) | 8.027182662 ft³ |
| 100 gal (imp) | 16.05436532 ft³ |
| 1000 gal (imp) | 160.5436532 ft³ |
Where it's used
Imperial Gallons are used for fuel economy in the UK (miles per gallon), while cubic feet appear in natural gas billing (ccf, Mcf). Both measure volume (capacity), so the conversion is a fixed factor.
Imperial Gallon to other volume units
| Conversion | 1 gal (imp) equals |
|---|---|
| imperial gallon to cubic meter | 0.00454609 m³ |
| imperial gallon to liter | 4.54609 L |
| imperial gallon to milliliter | 4546.09 mL |
| imperial gallon to cubic centimeter | 4546.09 cm³ |
| imperial gallon to cubic foot | 0.1605436532 ft³ |
| imperial gallon to cubic inch | 277.4194328 in³ |
| imperial gallon to US gallon | 1.200949926 gal (US) |
Frequently asked questions
How many cubic feet are in 1 imperial gallon?
1 gal (imp) = 0.1605436532 ft³.
How do I convert imperial gallons to cubic feet?
Multiply the value in gal (imp) by 0.1605436532, or divide it by 6.228835459. For example, 15 gal (imp) × 0.1605436532 = 2.408154799 ft³.
Is the gal (imp) to ft³ conversion exact?
Yes. Both units are defined exactly, so the ratio is exact; its decimal form does not terminate and is shown here to 10 significant figures (more with the precision selector).
Sources
- Guide for the Use of the International System of Units (SI), NIST Special Publication 811, 2008 Edition, National Institute of Standards and Technology , Appendix B.8, "gallon [Canadian and U.K. (Imperial)]".
- Guide for the Use of the International System of Units (SI), NIST Special Publication 811, 2008 Edition, National Institute of Standards and Technology , Appendix B.8, "cubic foot (ft³)".
Last reviewed: . Factors are stored exactly and computed with 50-digit decimal arithmetic. See how we verify conversion factors.
Cite this page
APA
Scientific Converters. (2026, October 15). Convert Imperial Gallons to Cubic Feet. Retrieved October 17, 2026, from https://scientificconverters.com/volume/imperial-gallons-to-cubic-feet/
IEEE
Scientific Converters, "Convert Imperial Gallons to Cubic Feet," scientificconverters.com. Accessed: Oct. 17, 2026. [Online]. Available: https://scientificconverters.com/volume/imperial-gallons-to-cubic-feet/