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Convert liters to gallons

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Convert liter values to liquid gallons (US) and vice versa instantly, with custom volume conversion parameters.
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Conversion Result
15 L = 3.962581 gal (US)

Liter to Gallon (US) Conversion Table

Liter (L) Gallon (US gal)
0.01 L0.0026417205 gal (US)
0.1 L0.0264172052 gal (US)
1 L0.2641720524 gal (US)
2 L0.5283441047 gal (US)
3 L0.7925161571 gal (US)
5 L1.3208602618 gal (US)
10 L2.6417205236 gal (US)
20 L5.2834410472 gal (US)
50 L13.2086026179 gal (US)
100 L26.4172052358 gal (US)
1000 L264.1720523581 gal (US)

Gallons and liters are the two primary large-volume liquid measurement units used worldwide to express automotive fuel gas tank capacity, gasoline retail sales, beverage bottling, aquarium sizes, paint cans, and chemical drum capacity. While the US liquid gallon (gal) is the standard customary unit used in the United States and US territories, the liter (L) is the official International System of Units (SI) volume standard used across Europe, Asia, Latin America, Canada, Australia, and all international fuel pumps.

Our free online Gallons to Liters Converter provides instant, high-precision volume conversions in both directions:

  • US Customary Gallons to Liters: Multiply US gallons by 3.785411784 (exact international standard).
  • Imperial Gallons (UK / Caribbean) to Liters: Multiply Imperial gallons by 4.54609 (exact UK standard).
  • Liters to US Customary Gallons: Divide liters by 3.785411784 (or multiply by 0.26417205).

Comparing US Customary Gallons vs. Imperial Gallons

Because the United States and the United Kingdom defined their customary gallons differently in the 18th and 19th centuries, converting gallons to liters depends on which gallon system you are using:

Gallon System Primary Regions of Usage Exact Volume in Cubic Inches Exact Volume in Liters (L)
US Liquid Gallon United States, US territories, Liberia 231.000 cu in (Queen Anne’s Wine Gallon) 3.785411784 L (exact)
Imperial Gallon (UK) United Kingdom, Canada, Caribbean nations 277.419 cu in (10 lbs water at 62 °F) 4.546090000 L (exact)
US Dry Gallon US agricultural grain bushels 268.802 cu in (1/8th US Winchester bushel) 4.404883770 L (exact)

Step-by-Step Calculation Example

To convert 15 US gallons to liters:

15 gal × 3.785411784 = 56.781177 liters

Thus, 15 US gallons is equal to approximately 56.78 L.


US Gallon to Liter Conversion Table

Below is a quick reference lookup table converting customary liquid volumes from 0.01 gallons up to 1,000 gallons:

US Gallons (gal) Liters (L) Automotive, Fuel & Household Benchmark
0.01 gal 0.037854 L 37.85 mL (1.28 US fl oz)
0.10 gal 0.378541 L 378.54 mL (12.8 US fl oz)
0.50 gal 1.892706 L Half-gallon milk carton (≈ 1.89 L)
1.00 gal 3.785412 L 1.0 US Gallon Exact Benchmark (3.785 L)
2.00 gal 7.570824 L 2-gallon garden watering can
5.00 gal 18.927059 L 5-gallon office water cooler jug (≈ 18.93 L)
10.00 gal 37.854118 L Standard 10-gallon aquarium tank
13.21 gal 50.000000 L 50-Liter European compact car gas tank benchmark
20.00 gal 75.708236 L Full-size pickup truck / SUV gas tank (~75.7 L)
55.00 gal 208.197648 L Industrial 55-gallon steel oil drum (≈ 208.2 L)
100.00 gal 378.541178 L 378.54 Liters
1,000.00 gal 3,785.411784 L 3,785.41 Liters (3.785 m³)

History & Standards: US Wine Gallon vs. French Metric Liter

Queen Anne’s Wine Gallon (1707) and the US Gallon

The word gallon derives from Old Northern French galon (meaning liquid container). In 1707, during the reign of Queen Anne of Great Britain, Parliament standardized the wine gallon as a cylinder 7 inches in diameter and 6 inches deep, creating a volume of exactly 231 cubic inches. When the United States declared independence, it retained the 231-cubic-inch wine gallon as its official US liquid gallon. In 1959, international standards locked 1 US inch to 2.54 cm, fixing 1 US gallon to 3.785411784 liters.

The Imperial Gallon of 1824

In 1824, Great Britain abolished historical wine and ale gallons, replacing them with the Imperial gallon defined as the volume of 10 pounds of distilled water at 62 °F (277.42 cubic inches = 4.54609 liters). This explains why British Imperial gallons are roughly 20% larger than US customary gallons.

The SI Metric Liter (L)

Created in France in 1795, the liter was defined as 1 cubic decimeter (10 cm × 10 cm × 10 cm = 1,000 cm³). Today, liters are the official global metric volume unit for gas pumps and beverage bottling.


To convert liters back to gallons, visit our Liters to Gallons Converter. For kitchen baking and recipe conversions, check our Ml to Cups Converter. For calculating fuel expenses, explore our Fuel Cost Calculator or Conversion Calculator.


Frequently Asked Questions (FAQ)

How many liters are in 1 US gallon?

There are exactly 3.785411784 liters in 1 US liquid gallon (commonly rounded to 3.785 L).

How many liters are in 1 Imperial gallon (UK)?

There are exactly 4.54609 liters in 1 UK Imperial gallon.

How many liters is a 15-gallon car gas tank?

A 15-gallon US gas tank holds 15 × 3.785412 = 56.78 liters of fuel.

Why is a 5-gallon water jug equal to 18.9 liters?

Because 1 US gallon equals 3.7854 liters: 5 × 3.7854 = 18.927 liters (labeled as 18.9L or 19L in metric countries).