Convert US gallons to liters for fuel, water tanks, aquariums, recipes, and other liquid measurements.
How to Convert US Gallons to Liters
One US liquid gallon contains exactly 3.785411784 liters. To convert US gallons to liters, multiply by 3.785411784.
Liters = US gallons × 3.785411784
Example: Convert 5 US Gallons to Liters
5 × 3.785411784 = 18.92705892 L
Therefore, 5 US gallons is approximately 18.93 liters.
US Gallons to Liters Conversion Table
| US gallons (US gal) | Liters (L) |
|---|---|
| 1 US gal | 3.78541 L |
| 2 US gal | 7.57082 L |
| 5 US gal | 18.9271 L |
| 10 US gal | 37.8541 L |
| 20 US gal | 75.7082 L |
| 25 US gal | 94.6353 L |
| 50 US gal | 189.271 L |
| 100 US gal | 378.541 L |
| 500 US gal | 1,892.71 L |
| 1,000 US gal | 3,785.41 L |
Why Do Water-Cooler Bottles Show Gallons and Litres?
A large water-cooler bottle is a familiar example of where a Gallon to Litre conversion is useful in daily life. Many bottles and product labels display both measurements, such as 5 US gallons and 18.9 litres. Although these numbers look different, they describe approximately the same volume of water.
Converting a 5-gallon water bottle to litres
One US liquid gallon contains exactly 3.785411784 litres. To convert gallons to litres, multiply the number of gallons by 3.785411784:
Litres = US gallons × 3.785411784
For a five-gallon water-cooler bottle:
5 × 3.785411784 = 18.92705892 litres
Manufacturers usually round this value to 18.9 L. This is why the same bottle may be described as a “5-gallon bottle” in the United States and an “18.9-litre bottle” in countries that use metric measurements.
Why are both units printed on the bottle?
Water bottles, dispensers and delivery equipment may be manufactured for several countries. Gallons remain familiar to customers in the United States, while litres are used throughout most of the world. Showing both units makes the bottle easier to identify without requiring customers, suppliers or delivery companies to perform the calculation themselves.
Dual-unit labelling is also helpful when a dispenser is advertised in litres but replacement bottles are sold in gallons. A Gallon to Litre converter lets the customer confirm that the bottle and dispenser have compatible capacities.
Common water-bottle capacities in gallons and litres
| Bottle capacity | Exact volume in litres | Typical rounded label |
|---|---|---|
| 1 US gal | 3.785 L | 3.8 L |
| 2 US gal | 7.571 L | 7.6 L |
| 3 US gal | 11.356 L | 11.3 L or 11.4 L |
| 4 US gal | 15.142 L | 15.1 L |
| 5 US gal | 18.927 L | 18.9 L |
Make sure you use the correct gallon
The familiar 5-gallon water-cooler bottle uses US liquid gallons. It does not use Imperial gallons. One Imperial gallon equals approximately 4.546 litres, so five Imperial gallons would equal about 22.73 litres rather than 18.9 litres.
This difference matters when comparing imported bottles, storage tanks or dispenser specifications. If a bottle is marked 5 gal / 18.9 L, the gallon measurement is based on the US liquid gallon.
How people use this conversion
People convert Gallon to Litre measurements when ordering bottled-water deliveries, choosing a compatible dispenser, estimating household or office water consumption, or comparing containers sold in different countries. For example, an office using four 5-gallon bottles each week consumes approximately 75.7 litres of water.
Using the Gallon to Litre calculator above provides a more precise result for any bottle or container size, including decimal quantities that may not appear in a standard conversion table.