Liters to Gallons Converter

Two gallons exist and they differ by 20% — convert litres to both the US and the imperial one.

Conversion table

Volume	In US gallons
1	0.26417 gal
2	0.52834 gal
3	0.79252 gal
4	1.0567 gal
5	1.3209 gal
10	2.6417 gal
15	3.9626 gal
20	5.2834 gal
25	6.6043 gal
30	7.9252 gal
40	10.5669 gal
50	13.2086 gal
60	15.8503 gal
70	18.4921 gal
75	19.8129 gal

🛢️ Volumes to remember

1 US gallon3.7854 L
1 imperial gallon4.5461 L
1 litre0.2642 US gal
50 L tank13.2 US gal

Buying fuel and liquids abroad

Always ask which gallon. The imperial one holds 20% more, so the same price per gallon is a very different price per litre.
To convert litres to US gallons in your head, divide by four and add 5%. Fifty litres is about 13.2 gallons.
The United Kingdom sells fuel by the litre but still quotes consumption in miles per imperial gallon — the two systems coexist on the same forecourt.
A US quart is a quarter of a US gallon, or 0.946 L, which is why an American litre bottle of milk looks slightly larger than a quart.

Two gallons, two histories

The US gallon descends from the English wine gallon of Queen Anne, defined as 231 cubic inches, which converts to exactly 3.785411784 litres. Britain abandoned that line in 1824 and redefined its gallon as the volume of ten pounds of water, arriving at 4.54609 litres, and then kept the same word. The result is two units 20% apart sharing a name, both still in daily use, and no way to tell them apart from context alone. Everything downstream inherits the split: pints, quarts and fluid ounces all come in two sizes.

Where the difference shows up at the pump

Fuel is where most people meet both gallons at once. American prices are per US gallon, so a price of 3.50 works out at 0.92 per litre. A British price of 3.50 per imperial gallon would be 0.77 per litre, a fifth cheaper for the same headline number — which is exactly why the United Kingdom sells fuel by the litre while still reporting economy in miles per imperial gallon. The same trap catches fuel economy figures: a car rated 40 mpg in Britain is only 33 mpg by American measurement, with no mechanical difference at all.

Who uses which gallon

United States, and Latin American countries that import American equipment: the US gallon of 3.785 L.
United Kingdom and Ireland: fuel sold in litres, consumption still quoted in miles per imperial gallon of 4.546 L.
Canada: sells fuel by the litre and quotes consumption in L/100 km, having abandoned gallons in the 1970s.
Most of the world uses litres exclusively for both.
Aviation fuel is bought in US gallons or in litres, and often converted to kilograms for weight and balance.
A barrel of oil is 42 US gallons, or 158.99 litres, and is used only for crude.

Volumes you can picture

A car fuel tank: 45–70 L, which is 12–18.5 US gallons.
A jerrycan: 20 L, or 5.28 US gallons.
A bathtub: 150–200 L, about 40–53 US gallons.
A domestic water heater: 150–300 L, or 40–79 US gallons.
A US gallon of water weighs 3.79 kg; an imperial gallon weighs 4.55 kg, which is where its ten-pound definition came from.
A swimming pool of 8 by 4 metres and 1.5 m deep holds 48,000 L, some 12,680 US gallons.

Worked examples

Tanks and fuel prices

A 50 litre tank

50 ÷ 3.785411784 = 13.21 US gallons
50 ÷ 4.54609 = 11.00 imperial gallons
Mental check: 50 ÷ 4 = 12.5, plus 5%

50 L = 13.21 US gal = 11.00 imp gal

Fuel at 1.60 per litre

1.60 × 3.785411784 = 6.06 per US gallon
1.60 × 4.54609 = 7.27 per imperial gallon
The same fuel, two very different headline prices

1.60/L = 6.06 per US gallon

Frequently Asked Questions

How many litres are in a gallon?

3.785411784 litres for the US gallon and 4.54609 litres for the imperial one — a difference of about 20%. Both figures are exact by definition, so the only question is which gallon a document means.

Why are there two different gallons?

Because Britain changed its mind and the United States did not. The US gallon kept the old English wine gallon of 231 cubic inches, while Britain redefined its gallon in 1824 as the volume of ten pounds of water. The two lines never reconverged, and the same split runs through pints, quarts and fluid ounces.

How do I convert litres to gallons in my head?

Divide by four and add about five per cent for US gallons. Fifty litres becomes 12.5 plus 0.7, so around 13.2. For imperial gallons, divide by four and subtract about ten per cent instead.

Is a UK pint bigger than a US pint?

Yes, by the same 20% as the gallons. An imperial pint is 568 mL and a US pint is 473 mL, which is why a pint of beer in London is noticeably larger than one in New York. Both are one eighth of their respective gallon.

How much does a gallon of water weigh?

A US gallon weighs about 3.79 kg, or 8.34 pounds. An imperial gallon weighs about 4.55 kg, or 10 pounds — which is not a coincidence, because the imperial gallon was defined in 1824 as exactly the volume of ten pounds of water.

Why does the UK sell fuel in litres but quote mpg?

Because the sale was metricated and the habit was not. Pumps have delivered litres since the 1980s, but drivers still describe consumption in miles per imperial gallon, so a British mpg figure is about 20% higher than an American one for the same car.