Gallons to Liters Converter

Type a number of US gallons and this converter shows the answer in liters instantly (1 gal = 3.78541 L). Below the converter you will find a ready-made gal to L table, and further down the formula with a worked example.

Gallons measure fuel, milk, water jugs, paint and aquariums in the United States. Converting to liters is useful when an American car manual lists an 18-gallon fuel tank (68.1 L), when a fish-keeping guide recommends a 20-gallon tank (75.7 L), or when comparing a gallon of milk with the 1-liter cartons sold elsewhere.

How to use the Gallons to Liters tool

1. Enter the value in US gallons in the Value box. Decimals such as 5.5 are fine.
2. The result in liters appears straight away, rounded to six significant digits.
3. Check the formula line under the result to see exactly how it was calculated.
4. Press ⇄ to convert liters back to US gallons, or pick any other unit from the lists.
5. Use Copy result, or look up common values in the conversion table.

Why use ToolOrca Gallons to Liters

• Exact factor: 1 gal = 3.78541 L
• Conversion table: gal to L
• Formula and worked example included
• Instant result as you type
• Converts to every other volume unit too
• Free, private and works offline

How to convert US gallons to liters

One US liquid gallon is 231 cubic inches, which is exactly 3.785411784 liters. A liter is one cubic decimeter, or 1,000 cubic centimeters. So 1 gal = 3.785411784 L exactly, and 1 L = 0.264172052 gal.

To convert US gallons to liters, multiply the number of US gallons by 3.785411784.

Worked example: 10 gal × 3.785411784 = 37.8541 L.

Quick mental math for gal to L

Multiply by 4 and take away 5%: 10 gal × 4 = 40, minus 2 = 38 L (exact 37.85 L). One US gallon is almost exactly 3¾ liters.

Need the opposite direction? Use the liters to US gallons converter, or switch units with the ⇄ button above.