Liters to Gallons Converter
One US liquid gallon equals exactly 3.785411784 liters. One imperial gallon (UK) equals exactly 4.54609 liters. Choose your gallon type below — the two differ by about 20%.
Formulas
For US liquid gallons:
US gallons = liters × 0.2641720523581484 liters = US gallons × 3.785411784
For imperial gallons:
imperial gallons = liters × 0.2199692482990877 liters = imperial gallons × 4.54609
Formula variables
- liters — volume in liters (L).
- US gallons — volume in US liquid gallons (gal).
- imperial gallons — volume in imperial (UK) gallons (imp gal).
- 3.785411784 — exact number of liters in one US liquid gallon, defined as 231 cubic inches.
- 4.54609 — exact number of liters in one imperial gallon, historically defined as the volume of 10 pounds of water at 62 °F.
Worked Examples
Example 1: 1 liter to US gallons
- Start: 1 L.
- Multiply: 1 × 0.2641720523581484.
- Result: 1 liter ≈ 0.264172 US gallons.
Example 2: 40 liters to US gallons
- Start: 40 L.
- Multiply: 40 × 0.2641720523581484 = 10.566882094325936.
- Result: 40 liters ≈ 10.5669 US gallons. This is the fuel capacity of many small cars.
Example 3: 40 liters to imperial gallons
- Start: 40 L.
- Multiply: 40 × 0.2199692482990877 = 8.798769931963508.
- Result: 40 liters ≈ 8.7988 imperial gallons. This is about 20% less than the US gallon equivalent.
Common Conversion Table (US Gallons)
| Liters (L) | US Gallons (gal) |
|---|---|
| 1 | 0.264172 |
| 5 | 1.320860 |
| 10 | 2.641721 |
| 20 | 5.283441 |
| 40 | 10.566882 |
| 50 | 13.208603 |
| 60 | 15.850323 |
| 100 | 26.417205 |
US vs Imperial Gallons
This is one of the most common sources of confusion in volume conversion. The two gallon definitions diverge because they were established independently and based on different reference points:
- The US liquid gallon was defined by the US as 231 cubic inches (this dates to the early 19th century).
- The imperial gallon was defined by the UK in 1824 as the volume of 10 pounds of distilled water at 62 °F and 30 inHg. It is approximately 277.42 cubic inches.
As a result, one imperial gallon is about 20% larger than one US gallon. When comparing fuel economy between countries, or when following recipes from a cookbook, always confirm which gallon is meant.
Real-World Uses
- Fuel: Fuel is sold by the liter in most of the world but by the US gallon in the United States. Understanding the conversion is essential for comparing prices and economy figures.
- Cooking and beverages: Recipes and drink mixers sometimes use gallons. A "gallon of milk" in the US means 3.785 L, while in the UK historically it meant 4.546 L.
- Shipping: Container volumes are often stated in cubic meters or liters; converting to gallons helps with US-based documentation.
- Aquariums and pools: Tank volumes are quoted in gallons (US or imperial) or liters, depending on the manufacturer's country.
Unit Definitions
Liter (L)
A metric unit of volume equal to exactly 1 cubic decimeter (0.001 cubic meter). It is not an SI unit but is accepted for use with SI. Since 1964 the liter has been defined by this exact equivalence to the cubic decimeter.
US Liquid Gallon (gal)
A US customary unit of volume equal to exactly 231 cubic inches, which is 3.785411784 liters. It is used in the US for fuel, beverages, and liquid chemicals.
Imperial Gallon (imp gal)
A UK unit of volume equal to exactly 4.54609 liters. It is used in the UK, Canada (historically), and some Caribbean countries for specific applications such as fuel economy (UK MPG).
Related Converters
- Gallons to Liters — reverse conversion
- Milliliters to Cups
- Cups to Milliliters
- All Volume Converters
Frequently Asked Questions
How many liters are in a US gallon?
One US liquid gallon equals exactly 3.785411784 liters. This is defined as 231 cubic inches exactly.
How many liters are in an imperial gallon?
One imperial gallon equals exactly 4.54609 liters, which is about 20% larger than a US gallon.
How do you convert liters to gallons?
Divide the number of liters by 3.785411784 to get US gallons, or divide by 4.54609 to get imperial gallons. Alternatively, multiply by 0.2641720523581484 for US gallons or 0.2199692482990877 for imperial gallons.
Are UK and US gallons the same?
No. They are about 20% different. One US gallon equals 0.832674 imperial gallons, and one imperial gallon equals 1.200950 US gallons.
Which gallon does the US use?
The United States uses the US liquid gallon (3.785411784 liters) for fuel, beverages, and most liquid measurements. It also has a separate "US dry gallon" (about 4.405 L) that is rarely used and is not the same as the imperial gallon.