TL;DR: Converting gallons to liters requires knowing which gallon is being used, as the US and UK systems differ. The standard conversion factors are precise and widely used in science and trade.
- 1 US liquid gallon is equal to 3.7854 liters.
- 1 UK imperial gallon is equal to 4.54609 liters.
- The US gallon is smaller than the UK imperial gallon by about 20%.
- To convert US gallons to liters, multiply the gallon value by 3.7854.
- To convert liters to US gallons, multiply the liter value by 0.26417.
How Many Liters Are in a Gallon?
One US liquid gallon contains exactly 3.785411784 liters. For most practical purposes, the conversion factor is shortened to 3.7854. This value is the standard for converting volume from the US customary system to the metric system.
The United Kingdom and some Commonwealth countries use the imperial gallon, which is larger. One imperial gallon is equal to exactly 4.54609 liters. Because of this difference, it is necessary to identify whether a measurement is in US gallons or imperial gallons before performing a conversion to liters.
US Gallons vs. Imperial Gallons
The primary difference between the US and imperial gallon is their volume. The US liquid gallon is legally defined as 231 cubic inches, while the imperial gallon is defined as the volume of 10 pounds of water at 62 °F, which equates to approximately 277.42 cubic inches. This makes the imperial gallon about 20% larger than the US gallon.
Both systems also define smaller units differently. For instance, a US pint is 16 US fluid ounces, while an imperial pint is 20 imperial fluid ounces. These differences cascade up to the gallon measurement.
| Feature | US Gallon (Liquid) | Imperial Gallon (UK) |
|---|---|---|
| Volume in Liters | 3.785411784 L | 4.54609 L |
| Volume in Cubic Inches | 231 cu in | ~277.42 cu in |
| Quarts per Gallon | 4 US quarts | 4 imperial quarts |
| Pints per Gallon | 8 US pints | 8 imperial pints |
| Fluid Ounces per Gallon | 128 US fl oz | 160 imperial fl oz |
Gallons to Liters Conversion Formulas
To convert a volume from gallons to liters, you multiply the number of gallons by the appropriate conversion factor. The formulas depend on which gallon system you are using.
- US Gallons to Liters: Liters = US Gallons × 3.78541
- Imperial Gallons to Liters: Liters = Imperial Gallons × 4.54609
For example, to convert 10 US gallons to liters, the calculation is 10 gal × 3.78541 = 37.8541 L. To convert 10 imperial gallons, it would be 10 gal × 4.54609 = 45.4609 L.
Common Gallon to Liter Conversion Table
A quick reference table provides immediate conversions for common volumes without needing a calculator. The table below shows conversions for both US and imperial gallons.
| Gallons | US Gallons to Liters (L) | Imperial Gallons to Liters (L) |
|---|---|---|
| 1 gal | 3.79 L | 4.55 L |
| 2 gal | 7.57 L | 9.09 L |
| 5 gal | 18.93 L | 22.73 L |
| 10 gal | 37.85 L | 45.46 L |
| 15 gal | 56.78 L | 68.19 L |
| 20 gal | 75.71 L | 90.92 L |
| 50 gal | 189.27 L | 227.30 L |
How to Convert Liters to Gallons
To convert liters to gallons, you divide the volume in liters by the conversion factor or multiply by its reciprocal. One liter is equal to approximately 0.26417 US liquid gallons or about 0.21997 imperial gallons.
The formulas for this reverse conversion are:
- Liters to US Gallons: US Gallons = Liters × 0.26417
- Liters to Imperial Gallons: Imperial Gallons = Liters × 0.21997
For instance, converting 50 liters to US gallons results in 50 L × 0.26417 = 13.2085 US gallons.
Frequently Asked Questions
Is 1 gallon equal to 4 liters? No, 1 US gallon is approximately 3.785 liters, which is slightly less than 4 liters. One imperial gallon is about 4.546 liters, which is more than 4 liters.
Are 4 liters in a gallon? No, 4 liters is a volume slightly larger than one US gallon (3.785 L) but smaller than one imperial gallon (4.546 L). Many beverage containers sold in metric regions are 4 liters, which is close to the US gallon size.
How much is 1 US gallon in litres? One US gallon is precisely 3.785411784 liters. For everyday calculations, this is commonly rounded to 3.785 or 3.79 liters.
How many gallons are in 1 liter? One liter contains approximately 0.264 US gallons or 0.220 imperial gallons. This means a liter is a little more than one US quart.