Conversion
Imperial Gallons to US gallons
1 imp gal = 1.20095 US gal, derived from exact unit definitions.
—
Swap ⇆| imp gal | US gal |
|---|---|
| 1 imp gal | 1.2009 US gal |
| 5 imp gal | 6.0047 US gal |
| 10 imp gal | 12.0095 US gal |
| 50 imp gal | 60.0475 US gal |
| 100 imp gal | 120.0950 US gal |
| 500 imp gal | 600.4750 US gal |
| 1,000 imp gal | 1,200.9499 US gal |
Formula
US gallons = imperial gallons × 1.200949926FAQ
How many US gallons in a imperial gallon?
1 imp gal = 1.20095 US gal. Multiply your imperial gallons value by 1.20095.
Is this exact?
Yes — these factors derive from exact definitions: 1 US gallon = 231 cubic inches, 1 imperial gallon = 4.54609 liters, 1 inch = 2.54 cm, 1 barrel = 42 US gallons.
Why do tank specs mix imperial gallons and US gallons?
US tank trade uses gallons and inches; engineering drawings and international suppliers use metric or cubic measures. This page bridges them without rounding drift.