US Gallon to Liter: Conversion, Formula & Chart
1 US gallon = 3.785411784 liters.
For almost all practical purposes, this number is rounded to 3.7854 liters or 3.79 liters.
The US gallon is a common unit of liquid volume in the United States. It is used for measuring gasoline, milk, water, paint, and other liquids. Because the US gallon is different from the UK Imperial gallon, it is important to use the correct gallon when converting to liters.
Use the US Gallon to Liter Converter below to convert any amount instantly, or use the formula and conversion charts for quick manual conversions.
US Gallon to Liter Converter
Convert US gallons to liters (L), or liters to US gallons, instantly.
Common conversions
What is a US gallon?
A US gallon, also called a US liquid gallon, is a unit of volume used in the United States to measure liquids. It is different from the UK Imperial gallon, which is larger.
- 1 US Liquid Gallon = 3.785411784 liters (approximately 3.79 L)
- 1 US Liquid Gallon = 128 US Fluid Ounces
- 1 US Liquid Gallon = 4 quarts
- 1 US Liquid Gallon = 8 pints
- 1 US Liquid Gallon = 16 cups
- 1 UK Imperial Gallon = 4.54609 Liters [This is why you must use US]
In the United States, gallons are commonly used to measure gasoline, milk, water, paint, and other liquids. For example, when you see a gallon-sized milk jug or water container in a US store, it refers to a US gallon.
The US gallon is also commonly used for aquariums and fish tanks. For example, a 50-gallon aquarium holds approximately 189 liters:
50 × 3.785411784 = 189.27 liters
How Many Liters in a Gallon of Water?
1 US gallon of water equals 3.785411784 liters, which is commonly rounded to 3.79 liters for everyday use.
This is one of the most common questions people have when converting between US gallons and liters. However, it is important to know that there are two different gallon measurements: the US gallon and the Imperial (UK) gallon.
The US gallon and Imperial gallon are different measurements:
- 1 US gallon = 3.785411784 L
- 1 Imperial gallon = 4.54609 L
A US gallon of water weighs about 8.34 pounds (3.78 kg) at typical room temperature. This is useful for shipping and fish tanks.
A liter measures volume, while a kilogram measures mass, so they are not directly equal. However, because water has a density close to 1 kg per liter under ordinary conditions, 1 liter of water weighs approximately 1 kg (2.20 lb).
| Measurement | Liters | Weight of Water |
|---|---|---|
| 1 US Gallon | 3.785 L | 8.34 lbs (3.78 kg) |
| 1 Imperial Gallon (UK) | 4.546 L | 10.0 lbs (4.54 kg) |
| 1 Liter | 1.0 L | 2.20 lbs (1.0 kg) |
| 5 US gallons | 18.927 L | 41.7 lbs (18.9 kg) |
Common Examples of Gallons of Water
Here are some everyday examples:
- 1 US gallon water bottle: about 3.785 liters
- 1-gallon gym water bottle: about 3.79 liters
- 2 US gallons of water: about 7.571 liters
- 5 US gallons of water: about 18.927 liters
For example, a 5-gallon US water jug holds about 18.93 liters of water and weighs approximately 41.7 pounds (18.9 kg) when full.
US Gallon vs UK Gallon vs Liter
Many people get confused. Don’t worry. Though they share the same name, the US gallon and UK gallon (imperial gallon) are different units of volume.
A US gallon is smaller than a UK gallon, while a liter is the metric unit commonly used to measure liquid volume.
| Measurement | Liters |
|---|---|
| 1 US Gallon | 3.78541 L |
| 1 UK Imperial Gallon | 4.54609 L |
| 1 Liter | 0.264 US gallons |
A US gallon contains about 3.79 liters, while a UK gallon contains about 4.55 liters. This makes the UK gallon roughly 20% larger than its US counterpart.
The US gallon contains 128 US fluid ounces, while the UK (Imperial) gallon contains 160 Imperial fluid ounces. Interestingly, an Imperial fluid ounce is smaller than a US fluid ounce: about 28.41 mL compared with 29.57 mL. The reason is that the UK gallon is larger overall, but it is divided into 160 fluid ounces instead of 128.
When a gallon is used in a US liquid-measurement context, it normally means the US liquid gallon. In the United States, fuel economy is commonly expressed in miles per US gallon (MPG). A UK gallon is 20% bigger.
Important: When converting gallons to liters, always check whether the measurement is a US gallon or UK (Imperial) gallon, as they are not the same size.
US Gallon to Liter Formula
Converting US gallons to liters is straightforward. You just need to multiply the number of US gallons by 3.785411784.
Use this simple formula:
For everyday calculations, you can use 3.79 instead of 3.785411784.
Step-by-Step Examples
Example 1: Convert 0.5 US gallons (half a gallon) to liters.
0.5 × 3.785411784 = 1.8927 L
So, 0.5 US gallon = 1.8927 L (approximately 1.89 L).
Example 2: Convert 1 US gallon to liters
1 × 3.785411784 = 3.785411784 liters
So, 1 US gallon = 3.785 L (approximately 3.79 L)
Example 2: Convert 2 US gallons to liters
2 × 3.785411784 = 7.570823568 liters
So, 2 US gallons ≈ 7.57 liters.
Example 3: Convert 5 US gallons to liters
5 × 3.785411784 = 18.92705892 liters
So, 5 US gallons ≈ 18.93 liters.
Example 4: Convert 15 US gallons (typical car fuel tank) to liters.
15 × 3.785411784 = 56.775 liters (approximately 56.78 L).
Reverse Formula (Liters to US Gallons)
If you have liters and need gallons:
Example: Convert 10 liters to US gallons.
10 ÷ 3.785411784 = 2.64 US gallons
Important: These formulas are for US liquid gallons only. If you’re converting UK (Imperial) gallons, use 4.546 instead of 3.785.
US Gallon to Liter Conversion Table
This table helps you convert quickly without a calculator. Perfect for USA kitchen and garage use. All values are rounded to two decimal places for everyday use.
| US Gallons | Liters (L) |
|---|---|
| 0.5 Gallon | 1.89 L |
| 1 Gallon | 3.79 L |
| 2 Gallon | 7.57 L |
| 3 Gallon | 11.36 L |
| 4 Gallon | 15.14 L |
| 5 Gallon | 18.93 L |
Small volumes (0.5–5 gal): Ideal for cooking, mixing paint, or measuring drinking water.
| US Gallons | Liters (L) |
|---|---|
| 5 Gallon | 18.93 L |
| 6 Gallon | 22.71 L |
| 7 Gallon | 26.50 L |
| 8 Gallon | 30.28 L |
| 9 Gallon | 34.07 L |
| 10 Gallon | 37.85 L |
| 12 Gallon | 45.42 L |
| 15 Gallon | 56.78 L |
| 20 Gallon | 75.71 L |
Medium volumes (5–20 gal): Useful for fuel tanks, aquarium sizes, or small storage containers.
| US Gallons | Liters (L |
|---|---|
| 20 Gallon | 75.71 L |
| 25 Gallon | 94.64 L |
| 50 Gallon | 189.27 L |
| 100 Gallon | 378.54 L |
Large volumes (20–100 gal): Helpful for rain barrels, fish ponds, or commercial liquid purchases.
Frequently Asked Questions
How many liters are in 1 US gallon?
There are exactly 3.78541 liters in 1 US liquid gallon. For quick calculation, you can use 3.79 liters.
How many gallons in 10 liters?
10 liters ÷ 3.78541 = 2.64172 US gallons. So 10L is about 2.64 US gallons.
Is 1 gallon the same as 4 liters?
No. 1 US gallon is 3.785 liters, slightly less than 4 liters. 1 UK gallon is 4.546 liters, slightly more than 4 liters.
How many 500 ml bottles in a gallon?
1 US gallon contains about 7.57 bottles of 500 mL each. In other words, seven full 500 mL bottles plus about 285 mL.
What is bigger, a gallon or a liter?
A gallon is bigger than a liter. 1 gallon = 3.78 liters. So a gallon is almost 4 times bigger than a liter.
Conclusion
Now you know how to convert US gallon to liter easily. Just multiply by 3.78541.
Use our converter at the top of the page for instant results. Perfect for cooking, fuel economy, water jugs, and aquarium calculations.
Explore more volume converters in our Volume Converter Hub.
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