How many liters in a gallon?

1 US gallon = 3.78541 liters. 1 imperial gallon = 4.54609 liters.

How many liters is 5 gallons?

5 US gallons × 3.78541 = 18.927 liters. A standard 5-gallon water jug holds about 18.9 L.

Is a US gallon the same as an imperial gallon?

No. A US gallon = 3.785 L; an imperial gallon (UK/Canada) = 4.546 L. The imperial gallon is about 20% larger. This matters when comparing fuel economy: a US mpg and a UK mpg are not the same.

US Gallons to Liters Converter

1 US gallon = 3.78541 liters. The imperial gallon (UK) = 4.54609 L — about 20% larger than a US gallon.

Inverse conversion

1 liter = 0.264172 US gallons. A 2-liter bottle = 0.528 gal. Note: the UK imperial gallon is larger.

Liters to US Gallons →

Note

This is the US liquid gallon (3.785 L), not the imperial gallon (4.546 L).

Formula

liters = gallons × 3.78541

Worked example

To convert 5 gallons to liters, multiply 5 × 3.78541 = 18.927 liters.

Quick reference table

gal (US)	L
0.5	1.892706
1	3.785412
2	7.570824
5	18.927059
10	37.854118
15	56.781177
20	75.708236

Unit definitions

US Gallon (gal (US))

The US gallon = 3.785411784 liters.

Liter (L)

The liter (L) is the standard metric volume unit.

Common use cases

Fuel economy (mpg vs L/100km)
Cooking and recipe conversion
Pool and tank volume

Related guides

US Gallon vs Imperial Gallon: What's the Difference?

The word 'gallon' refers to two different volumes depending on where you are. The US gallon is 3.785 liters; the imperial (UK) gallon is 4.546 liters — about 20% larger. Getting this wrong matters for fuel economy comparisons, brewing recipes, shipping, and any cross-border volume calculation.

Frequently asked questions

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