Gallons to Liters Converter
Enter a value below to convert US gallons to liters - one US gallon is exactly 3.785411784 L (1 liter is about 0.2642 gal). For the reverse, use our liters to gallons converter.
1 gal = 3.785412 L. Enter a value above to convert US gallons to liters. Need the reverse? See liters to gallons.
US gallon
- Definition
- A US gallon (symbol: gal) is a unit of volume in the US customary system, defined as exactly 231 cubic inches, which equals 3.785411784 liters. It is divided into 4 quarts, 8 pints, or 128 US fluid ounces.
- History / origin
- The US gallon derives from the British wine gallon of 231 cubic inches, which was standardized in England in 1707 under Queen Anne. The United States kept this measure, while the United Kingdom later replaced it with the larger imperial gallon of 4.54609 liters in 1824.
- Current use
- The US gallon is used mainly in the United States for fuel, milk, and other liquids sold by volume. The UK and Canada use the imperial gallon, which is larger, so a gallon does not mean the same amount on both sides of the Atlantic.
Liter
- Definition
- A liter (symbol: L) is a metric unit of volume equal to one cubic decimeter (1 L = 0.001 m³ = 1,000 cm³). It is accepted for use with the International System of Units (SI), though it is not an SI base unit.
- History / origin
- The liter was introduced in France in 1795 as part of the original metric system. It was once defined as the volume of one kilogram of water, but since 1964 it has been fixed at exactly one cubic decimeter, removing the small discrepancy that earlier definition carried.
- Current use
- The liter is used worldwide for measuring liquids - beverages, fuel, and household quantities - and for labeling container capacity in every country that uses the metric system.
Gallon to liter conversion table
| US gallon [gal] | Liter [L] |
|---|---|
| 0.1 gal | 0.3785411784 L |
| 0.5 gal | 1.892705892 L |
| 1 gal | 3.785411784 L |
| 2 gal | 7.570823568 L |
| 5 gal | 18.92705892 L |
| 10 gal | 37.85411784 L |
| 25 gal | 94.6352946 L |
| 50 gal | 189.2705892 L |
| 100 gal | 378.5411784 L |
| 500 gal | 1,892.705892 L |
| 1,000 gal | 3,785.411784 L |
Popular gallon to liter conversions
Everyday fuel, water-bottle, and drum sizes in liters, rounded to two decimals - the gallon values people look up most.
| US gallon [gal] | Liter [L] |
|---|---|
| 1 gal | 3.79 L |
| 2 gal | 7.57 L |
| 3 gal | 11.36 L |
| 5 gal | 18.93 L |
| 10 gal | 37.85 L |
| 15 gal | 56.78 L |
| 20 gal | 75.71 L |
| 25 gal | 94.64 L |
| 50 gal | 189.27 L |
| 100 gal | 378.54 L |
How to convert gallons to liters
To convert US gallons to liters, multiply the number of gallons by 3.785411784. For example, 5 gal × 3.785411784 = 18.93 liters (or divide by 0.2641720524).
One US gallon is defined as exactly 3.785411784 liters, so converting US gallons to liters is a single multiplication - no rounding is needed in the definition itself:
liters = US gallons × 3.785411784
1 gal = 3.785411784 L · 1 L = 0.2641720524 gal
Example. To convert 10 US gallons to liters, multiply by 3.785411784: 10 gal = 10 × 3.785411784 = 37.85 L. Going the other way, 20 liters is 20 ÷ 3.785411784 = 5.28 gal.
When you need to convert gallons to liters
Gallon-to-liter conversion is what you reach for when a US gallon volume has to fit a metric system. Common cases:
- Filling a fuel tank or estimating fuel use abroad, where pumps and prices are set per liter.
- Setting up an aquarium from a US gallon rating when dosing and equipment specs are in liters.
- Ordering water, fuel, or chemicals in liters to match drums and jerricans sold by gallon in the US.
- Following a US recipe, pool, or cleaning-solution guide in gallons on metric measuring equipment.
- Recording a tank or container capacity in liters for an international form or product label.
Frequently asked questions
How many liters is 1 gallon?
One US gallon equals 3.785411784 liters - close to four liters. A UK (imperial) gallon is larger, at 4.54609 liters.
How do I convert gallons to liters?
Multiply the number of US gallons by 3.785411784, or divide by 0.2641720524. For example, 5 gal = 5 × 3.785411784 = 18.93 liters.
Is 1 gallon exactly 3.785411784 liters?
Yes - exactly, by definition. A US gallon is defined as 231 cubic inches, which works out to 3.785411784 liters, so it is not a rounded approximation.
How many liters is 5 gallons?
5 US gallons equals 18.93 liters (18.927058920 L to be exact) - the size of a common water-cooler bottle.
How many liters is 10 gallons?
10 US gallons equals 37.85 liters (37.854117840 L to be exact).
Is a US gallon the same as a UK gallon?
No. A US gallon is 3.785411784 liters, while a UK (imperial) gallon is 4.54609 liters - about 20 percent larger. This page converts US gallons.
How do I convert gallons to liters in my head?
Multiply the gallons by four for a quick estimate, since one US gallon is close to four liters. For example, 5 gallons is about 20 L, and the exact value is 18.93 L.
How many gallons is 1 liter?
One liter equals 0.2641720524 US gallons. To convert liters to gallons, divide by 3.785411784.
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