US liquid gallon to Imperial gallon
gal
imp gal
Conversion History
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|---|---|---|
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Quick Reference Table (US liquid gallon to Imperial gallon)
| US liquid gallon (gal) | Imperial gallon (imp gal) |
|---|---|
| 0.5 | 0.41633709231622074226 |
| 1 | 0.83267418463244148452 |
| 2 | 1.66534836926488296905 |
| 5 | 4.16337092316220742262 |
| 10 | 8.32674184632441484524 |
| 50 | 41.63370923162207422621 |
About US liquid gallon (gal)
The US liquid gallon is a unit of volume equal to 4 quarts, 8 pints, or 128 US fluid ounces, approximately 3.785 liters. It is the primary large liquid volume unit in the United States, used for fuel pricing at the pump, milk and juice packaging, and paint. US fuel economy is measured in miles per gallon (MPG). The US gallon is about 17% smaller than the UK imperial gallon (4.546 L), causing significant differences in fuel economy comparisons.
A gallon jug of milk is 3.785 L. Petrol (gasoline) is priced per US gallon at every US fuel station.
About Imperial gallon (imp gal)
The imperial gallon is a unit of volume defined as exactly 4.54609 liters, used in the United Kingdom, Canada, and some Commonwealth nations. It is approximately 20% larger than the US liquid gallon. Fuel economy in the UK is expressed in miles per imperial gallon. The imperial gallon divides into 8 imperial pints, each of 568 mL. The UK officially metricated fuel sales to liters in the 1980s–1990s, but miles per imperial gallon remains the legal unit for new car fuel economy labels.
UK car fuel economy figures are expressed in miles per imperial gallon. One imperial gallon equals 8 standard UK pints of beer.
US liquid gallon – Frequently Asked Questions
Why does the US still price fuel per gallon when the rest of the world uses liters?
US fuel infrastructure — pumps, tax law, pipeline contracts, and consumer expectations — is built around the gallon. Federal and state fuel taxes are levied per gallon; EPA fuel economy standards use miles per gallon; and consumers benchmark prices against a gallon reference ("$3 a gallon"). Switching to liters would require reprogramming every pump, rewriting tax code, and re-educating 330 million people who compare prices by the gallon. Canada made the switch in the 1970s during a broader metrication push, but the US never had the political will for a comprehensive changeover.
Why is the US gallon smaller than the UK gallon?
The US gallon (3.785 L) is based on the Queen Anne wine gallon of 1707 (231 cubic inches). The UK imperial gallon (4.546 L) was defined in 1824 as the volume of 10 pounds of water. The two systems diverged after US independence.
How does US MPG compare to L/100km?
To convert: L/100km = 235.2 ÷ MPG (US). A car achieving 30 MPG uses about 7.8 L/100km. UK MPG values are always higher than US MPG for the same car because the imperial gallon is larger.
How many gallons of water does a person drink per day?
Recommended daily water intake is about 2–3 liters (roughly 0.5–0.8 US gallons). The commonly cited "8 glasses a day" ≈ 64 fl oz ≈ 0.5 gallons ≈ 1.9 liters.
How many gallons does a car fuel tank hold?
Most US passenger cars have fuel tanks of 10–20 gallons (38–76 liters). Compact cars are typically 10–13 gallons; mid-size cars 14–17 gallons; SUVs and trucks 18–36 gallons.
Imperial gallon – Frequently Asked Questions
How many liters are in an imperial gallon?
One imperial gallon is defined as exactly 4.54609 liters — approximately 20% more than the US liquid gallon (3.785 L).
Does the UK still use gallons?
The UK switched fuel sales to liters in the 1990s. However, miles per gallon (imperial) remains the legal unit for car fuel economy on new vehicle labels. Road speed is in mph and distances are in miles, so imperial gallons remain embedded in UK motoring.
How does UK MPG differ from US MPG?
UK MPG uses the imperial gallon (4.546 L); US MPG uses the US gallon (3.785 L). Multiply UK MPG by 0.832 to get US MPG. A car rated 40 UK MPG ≈ 33 US MPG.
How many pints are in an imperial gallon?
There are exactly 8 imperial pints in one imperial gallon. Each imperial pint is 568 mL, compared to 473 mL for a US pint.
Is the imperial gallon still used in Canada?
Canada officially metricated in the 1970s and fuel is sold in liters. However, some older Canadians and certain agricultural contexts still reference imperial gallons informally. Canadian and UK imperial gallons are identical (4.54609 L).