Convert US gallons to liters, both ways.
Type US gallons and read the exact liters, or type liters to convert back. The result updates live, with milliliters, quarts and the Imperial gallon equivalent for context and a one-click copy.
Your value
Edit either box. The formula is liters = US gallons times 3.78541, and US gallons = liters divided by 3.78541.
56.7812 LWhat this means
Common gallons to liters values
| US gallons | Liters | Liters (rounded) | Rough guide |
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How the conversion works
The Gallon-to-Liter Conversion Factor
One US gallon equals exactly 3.78541 liters. To convert US gallons to liters, multiply by 3.785. This is the US liquid gallon, the standard for fuel, milk, paint, and most volume measurements in the United States. The UK Imperial gallon (4.546 L) is different.
Why You'll Need This Conversion
US users encounter liters when traveling abroad (fuel stations sell by liter), reading European product specifications, ordering wine or olive oil from European sources, comparing international fuel economy figures, and reading international news. Converting from familiar gallons to liters helps you make sense of foreign quantities.
Reference Conversions
1 US gal = 3.785 L. 5 US gal = 18.93 L (typical jerry can). 15 US gal = 56.78 L. 20 US gal = 75.71 L (large SUV tank). 50 US gal = 189.27 L. 100 US gal = 378.54 L (small water tank).
Fuel Economy Translation
European fuel economy is given in L/100km (lower is better). US gives mpg (higher is better). The relationship: mpg × L/100km ≈ 235. So 30 mpg ≈ 7.8 L/100km, and 8 L/100km ≈ 29 mpg. Knowing this lets you compare car efficiency across markets.
Common questions
How many liters is 15 gallons?
15 US gallons equals 56.78 liters.
Is the UK gallon the same?
No, UK Imperial gallon = 4.546 L, about 20% larger than US gallon. This converter uses US gallons. For Imperial, multiply by 4.546 instead.
How much fuel does a typical car tank hold in liters?
US sedans: 45-65 L (12-17 US gal). Larger SUVs and pickups: 75-150 L (20-40 US gal). European cars often have smaller tanks (40-55 L).
How do gallons relate to quarts and cups?
1 US gal = 4 quarts = 8 pints = 16 cups = 128 US fluid oz = 3.785 L.
How heavy is a gallon of water?
1 US gallon of water weighs about 8.34 lbs (3.785 kg) at room temperature.
All conversion runs in your browser. Nothing is uploaded. 1 US liquid gallon is exactly 3.78541 liters by definition, so these results are precise, not approximate. The UK Imperial gallon is a different unit at 4.54609 liters.