Gallons to Liters 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
US liquid gallons to liters:
L = US gal × 3.785411784
Imperial gallons to liters:
L = imp gal × 4.54609
Reverse (liters to gallons):
US gal = L × 0.2641720523581484 imp gal = L × 0.2199692482990877
Formula variables
- US gal — volume in US liquid gallons, defined as exactly 231 cubic inches.
- imp gal — volume in imperial (UK) gallons, defined as exactly 4.54609 liters.
- L — volume in liters.
- 3.785411784 — exact liters per US liquid gallon.
- 4.54609 — exact liters per imperial gallon.
Worked Examples
Example 1: 1 US gallon to liters
- Start: 1 US gal.
- Multiply: 1 × 3.785411784 = 3.785411784.
- Result: 1 US gallon = 3.785411784 liters exactly.
Example 2: 10 US gallons to liters
- Start: 10 US gal.
- Multiply: 10 × 3.785411784 = 37.85411784.
- Result: 10 US gallons = 37.854 liters. This is roughly the fuel capacity of a mid-size car's tank.
Example 3: 1 imperial gallon to liters
- Start: 1 imp gal.
- Multiply: 1 × 4.54609 = 4.54609.
- Result: 1 imperial gallon = 4.54609 liters exactly.
Common Conversion Table
US liquid gallons to liters:
| US Gallons (gal) | Liters (L) |
|---|---|
| 1 | 3.785412 |
| 2 | 7.570824 |
| 5 | 18.927059 |
| 10 | 37.854118 |
| 15 | 56.781177 |
| 20 | 75.708236 |
| 25 | 94.635295 |
| 50 | 189.270589 |
| 100 | 378.541178 |
Imperial gallons to liters:
| Imperial Gallons (imp gal) | Liters (L) |
|---|---|
| 1 | 4.546090 |
| 2 | 9.092180 |
| 5 | 22.730450 |
| 10 | 45.460900 |
| 20 | 90.921800 |
| 50 | 227.304500 |
Real-World Uses
- Fuel: Fuel is sold by the US gallon in the US, by the imperial gallon historically in the UK, and by the liter almost everywhere else. Comparing fuel economy across systems requires this conversion.
- Cooking and beverages: Recipes and drink mixers may use gallons; a "gallon of milk" in the US is 3.785 L, while an imperial gallon is 4.546 L.
- Aquariums and pools: Tank and pool volumes are often quoted in gallons (US or imperial) or liters.
- Industrial and chemical: Chemical volumes are usually in liters or cubic meters; US-based documentation may also use gallons.
Unit Definitions
US Liquid Gallon (gal)
A US customary unit of volume equal to exactly 231 cubic inches, which is exactly 3.785411784 liters. It is used in the US for fuel, beverages, and most liquid measurements. There is also a "US dry gallon" (about 4.405 L) that is rarely used and is not the same as the imperial gallon.
Imperial Gallon (imp gal)
A British imperial unit of volume defined in 1824 as the volume of 10 pounds of distilled water at 62 °F and 30 inHg. This works out to exactly 4.54609 liters. The imperial gallon is about 20% larger than the US gallon.
Liter (L)
A metric unit of volume equal to exactly 1 cubic decimeter (0.001 m³). It is accepted for use with the SI but is not itself an SI unit. Its value has been fixed since 1964 by this exact equivalence.
Related Converters
- Liters to Gallons — reverse conversion
- Imperial Gallons to Liters
- Cubic Meters to Liters
- All Volume Converters
Frequently Asked Questions
How many liters in a US gallon?
One US liquid gallon equals exactly 3.785411784 liters.
How many liters in an imperial gallon?
One imperial gallon equals exactly 4.54609 liters, about 20% larger than the US gallon.
How do you convert gallons to liters?
For US gallons, multiply by 3.785411784. For imperial gallons, multiply by 4.54609. For example, 5 US gal × 3.785411784 = 18.927 L.
Are UK and US gallons the same?
No. They differ by about 20%. One US gallon equals 0.832674 imperial gallons; one imperial gallon equals 1.200950 US gallons.
What is 5 gallons in liters?
5 US gallons = 18.92705892 liters. 5 imperial gallons = 22.73045 liters.