Gallons to Liters

Gallons to Liters Conversion Formula

To convert US gallons to liters, use this simple formula:

The US gallon is defined as exactly 3.785411784 liters. This is the US liquid gallon; the imperial (UK) gallon is larger at 4.54609 liters, so always confirm which gallon you mean.

Step-by-Step Volume Conversion Guide

1. Take your volume in US gallons
2. Multiply it by 3.785412 (the number of liters in one US gallon)
3. Get your result in liters

Common Gallons to Liters Conversions

Practical Applications of Gallons to Liters Converter

• Fuel: Filling up abroad where pumps are priced per liter
• Aquariums: Converting a US-rated tank capacity to liters
• Cooking & brewing: Scaling US batch recipes to metric
• Water storage: Sizing tanks, barrels and containers
• Automotive: Coolant, oil and washer fluid capacities
• Paint: Estimating coverage from US-labeled cans

History of Volume Measurement

The US gallon traces back to the English wine gallon of 231 cubic inches and is now standardized as exactly 3.785411784 liters. The liter is the metric unit of volume equal to one cubic decimeter. Because the imperial gallon (4.54609 L) is about 20% larger, US and UK fuel-economy and capacity figures are not directly comparable.

Quick Conversion Tips

For quick approximations, remember: 1 US gallon ≈ 3.8 L. To estimate liters from gallons, multiply by 4 and subtract a little: 5 gal × 4 = 20, actual is 18.93 L. For precise results, always use the exact factor of 3.785412.