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Gallons to Liters Converter

Understanding Gallons and Liters

Gallons and liters are both units of volume, but they come from different measurement systems. The gallon is used primarily in the United States (US gallon = 3.785 L) and the United Kingdom (Imperial gallon = 4.546 L). The liter is the standard metric unit used worldwide. Understanding the conversion is essential for international cooking, fuel economy comparisons, and scientific applications.

How the Conversion Works

To convert US gallons to liters, multiply by 3.78541. For UK gallons, multiply by 4.54609. The difference exists because the US gallon is based on the wine gallon (231 cubic inches) while the UK gallon is based on 10 pounds of water. This converter automatically detects which gallon type you're using based on your selection.

Frequently Asked Questions

What's the difference between US and UK gallons?

A US gallon equals 3.785 liters (128 fl oz), while a UK/Imperial gallon equals 4.546 liters (160 UK fl oz). The UK gallon is approximately 20% larger than the US gallon.

How do I convert gallons to liters?

Multiply US gallons by 3.78541 or UK gallons by 4.54609. For example, 5 US gallons = 5 × 3.785 = 18.93 liters.

Which countries use gallons?

The US uses US gallons for fuel and liquids. The UK officially uses liters but still references gallons informally. Some Caribbean and Latin American countries also use US gallons.

Why are there different gallon sizes?

The US gallon (231 cubic inches) was based on the English wine gallon, while the UK Imperial gallon was defined in 1824 as the volume of 10 pounds of water at 62°F.

How many liters in a gallon of gas?

In the US, 1 gallon of gas = 3.785 liters. Gas stations in metric countries sell fuel by the liter. To compare prices, divide the per-gallon price by 3.785.

How do I convert fuel economy from MPG to L/100km?

Divide 235.215 by the MPG value. For example, 30 MPG = 235.215 ÷ 30 = 7.84 L/100km. Lower L/100km means better fuel economy.