US gallons to UK gallons
1 US gallon = 0.832674 UK gallons
Type a value in US gallons (gal) to get UK gallons (imp gal) straight away. A US gallon is smaller than a UK gallon, so the number goes down. Both units belong to volume, measured here against the liter.
1 gal = 0.83267418 imp gal
Formula
imp gal = gal × 0.83267418
One US gallon is 0.83267418 UK gallons, so multiply by that factor. You can also divide by 1.20095, the number of US gallons in one UK gallon. Here gal is the value in US gallons and imp gal is the result in UK gallons.
Worked example: 5 US gallons × 0.83267418 = 4.16337 UK gallons.
US gallons to UK gallons table
| US gallons (gal) | UK gallons (imp gal) |
|---|---|
| 1 gal | 0.832674 imp gal |
| 2 gal | 1.66535 imp gal |
| 3 gal | 2.49802 imp gal |
| 4 gal | 3.3307 imp gal |
| 5 gal | 4.16337 imp gal |
| 6 gal | 4.99605 imp gal |
| 7 gal | 5.82872 imp gal |
| 8 gal | 6.66139 imp gal |
| 9 gal | 7.49407 imp gal |
| 10 gal | 8.32674 imp gal |
| 15 gal | 12.4901 imp gal |
| 20 gal | 16.6535 imp gal |
| 25 gal | 20.8169 imp gal |
| 30 gal | 24.9802 imp gal |
| 40 gal | 33.307 imp gal |
| 50 gal | 41.6337 imp gal |
| 60 gal | 49.9605 imp gal |
| 75 gal | 62.4506 imp gal |
| 100 gal | 83.2674 imp gal |
Everyday US gallons in UK gallons
| What it is | gal | imp gal |
|---|---|---|
| a milk jug (US) | 1 gal | 0.832674 imp gal |
| a water-cooler bottle | 5 gal | 4.16337 imp gal |
| a compact car tank (about) | 13 gal | 10.8248 imp gal |
| an SUV tank (about) | 20 gal | 16.6535 imp gal |
| a standard oil drum | 55 gal | 45.7971 imp gal |
Quick estimate in your head
Multiply by about 0.83. For 5 gal that gives 4.15 imp gal against an exact 4.16337 imp gal, an error of 0.3%.
Watch out for
- A US gallon (3.785 L) is about 17% smaller than a UK gallon (4.546 L). Check which one a car manual or recipe means.
- UK fuel economy in miles per gallon uses the imperial gallon, so UK mpg figures look about 20% better than US ones for the same car.
About the units
US gallon (gal). The US liquid gallon, exactly 231 cubic inches or about 3.785 L. Used for fuel in the US.
UK gallon (imp gal). The imperial gallon, exactly 4.54609 L, about 20% larger than a US gallon.
Going the other way, 1 UK gallon is 1.20095 US gallons.
Questions
How many UK gallons are in 1 US gallon?
1 US gallon is 0.832674 UK gallons, and 1 UK gallon is 1.20095 US gallons.
How do I convert US gallons to UK gallons?
Use imp gal = gal × 0.83267418. For example, 5 US gallons × 0.83267418 = 4.16337 UK gallons.
Are US and UK measures the same?
No. This page uses US customary units. A UK gallon is 4.546 L against 3.785 L in the US, and a UK pint is 568 mL against 473 mL.
How much is a standard oil drum in UK gallons?
55 gal is 45.7971 imp gal.
Source for the conversion factor: NIST Handbook 44, Appendix C (units of volume).
Related conversions
- UK gallons to US gallons
- US gallons to liters
- liters to UK gallons
- UK gallons to liters
- liters to US gallons
- milliliters to US fluid ounces