Gallon (imperial) to Gallon (US liquid) Converter
1 imperial gallon is about 1.200949926 US gallons. Convert imperial gallons (imp gal) to US gallons (gal) below: type a value and the result updates as you type.
imp gal to gal calculator
Result
Gallon (imperial) to Gallon (US liquid) conversion
1 imp gal ≈ 1.200949926 galone imperial gallon in US gallons
1 gal ≈ 0.8326741846 imp galone US gallon in imperial gallons
Gallon (imperial) (imp gal): Exactly 4.54609 liters.
Gallon (US liquid) (gal): Exactly 231 cubic inches (3.785411784 liters).
Source:Gallon (imperial): Weights and Measures Act 1985 (UK): imperial gallon = 4.54609 liters; Gallon (US liquid): NIST Special Publication 811 (2008), Appendix B.8 (US liquid measures derive from the exact 231 cubic inch gallon)
How to convert imperial gallons to US gallons
To convert imperial gallons to US gallons, multiply the number of imperial gallons by about 1.200949926.
Formula
gal = imp gal × 1.200949926
The factor is rounded here. The calculator uses the exact value.
Examples
- 5 imp gal = 5 × 1.200949926 ≈ 6.004749628 gal
- 25 imp gal = 25 × 1.200949926 ≈ 30.02374814 gal
- 100 imp gal = 100 × 1.200949926 ≈ 120.0949926 gal
Gallon (imperial) to Gallon (US liquid) conversion table
| Gallon (imperial) (imp gal) | Gallon (US liquid) (gal) |
|---|---|
| 0.1 imp gal | 0.1200949926 gal |
| 0.5 imp gal | 0.6004749628 gal |
| 1 imp gal | 1.200949926 gal |
| 2 imp gal | 2.401899851 gal |
| 3 imp gal | 3.602849777 gal |
| 5 imp gal | 6.004749628 gal |
| 10 imp gal | 12.00949926 gal |
| 20 imp gal | 24.01899851 gal |
| 25 imp gal | 30.02374814 gal |
| 50 imp gal | 60.04749628 gal |
| 100 imp gal | 120.0949926 gal |
| 250 imp gal | 300.2374814 gal |
| 500 imp gal | 600.4749628 gal |
| 1000 imp gal | 1200.949926 gal |
Values rounded to 10 significant digits where needed.
Frequently asked questions
- How many US gallons are in one imperial gallon?
- One imperial gallon is about 1.200949926 US gallons.
- How do I convert US gallons to imperial gallons?
- To convert US gallons to imperial gallons, multiply the number of US gallons by about 0.8326741846. The formula is imp gal = gal × 0.8326741846.
- Is this conversion exact?
- Yes. Both units have exact definitions, but the factor has more decimal places than can be shown, so displayed results are rounded. The calculator works with 50 significant digits before rounding.
- Which is larger, a imperial gallon or a US gallon?
- A imperial gallon is about 1.200949926 times larger than a US gallon. In other words, a US gallon is about 0.8326741846 of a imperial gallon.