Convert gallons to liters (gal to L)
To convert gallons to liters, multiply the value in gallons by 3.785411784. It is used for fuel economy and fuel prices, water tanks, fish tanks, paint and milk bought in US gallons. This gallons to liters converter works both ways: type gallons or liters into either box above and the other box, the worked formula and the chart below update as you type.
The US liquid gallon (gal) is 231 cubic inches, which is exactly 3.785411784 liters. It is smaller than the imperial (UK) gallon of 4.54609 liters. In the US it measures fuel at the pump, milk, paint, water heaters and fish tanks. One US gallon is 3.78541 liters.
The liter (L), or litre, is a metric unit of volume. Since 1964 it has been defined as exactly one cubic decimeter, or 1,000 cubic centimeters. Going the other way, one liter equals 0.264172 US gallons. Liters are used for fuel, bottled drinks, engine sizes and fridge capacity in most of the world.
How to convert gallons to liters with this tool
- Type a number into the US gallons (gal) box — it starts at 1 gal as an example.
- Read the answer in the Liters (L) box and in the result panel, which also shows the formula with your number.
- To go the other way, type into the liters box, or press the swap button to open the Liters to Gallons converter with your value carried over.
- Choose how many decimal places you want, or tap a quick value such as 2 gal, 5 gal, 10 gal.
- Press Copy result to paste the conversion into a message, spreadsheet or note.
Gallons to Liters converter features
Converts both ways
Type in the gallons box to get liters, or in the liters box to get gallons. The other box follows instantly.
Exact factor
Calculations use 1 gal = 3.785411784 L, and rounding is applied only to the answer you see — choose Auto or 0–10 decimal places.
Formula with your number
The working is shown under the result, for example 1 gal × 3.785411784 = 3.7854 L, so you can check it or copy the method.
Quick values and chart
Tap common values like 2 gal, 5 gal, 10 gal, or read the gallons-to-liters table further down this page.
Handles UK gallons
If your figure is in imperial gallons, read the UK line under the result instead of the main US answer.
Gallons to Liters formula
The formula is L = gal × 3.785411784. It is exact because a US gallon is 231 cubic inches, which is exactly 3.785411784 liters.
The reverse formula is gal = L ÷ 3.785411784 — or use the Liters to Gallons converter. Three worked examples:
- One US gallon of milk: 1 gal × 3.785411784 = 3.7854 L
- A 15-gallon fuel tank: 15 gal × 3.785411784 = 56.7812 L
- A 55-gallon drum: 55 gal × 3.785411784 = 208.1976 L
US gallons vs UK (imperial) gallons
This page uses the US liquid gallon of 3.785411784 L, the gallon on American fuel pumps and milk jugs. The UK — and older Canadian and Australian sources — use the imperial gallon of exactly 4.54609 L, about 20% bigger. Mixing the two up is the most common gallon mistake: 10 gal = 37.8541 L, but 10 UK gal = 45.4609 L.
Gallons to Liters quick reference
The values people look up most often, worked out with the exact factor:
- 1 gal = 3.78541 L
- 1 L = 0.264172 gal
- 2 gal = 7.5708 L
- 5 gal = 18.9271 L
- 10 gal = 37.8541 L
- 15 gal = 56.7812 L
Quick tip: Multiply by 4 and subtract 5% for a quick estimate: 10 gal → 40 − 2 = 38 L, close to the exact 37.8541 L.
Related conversions: Liters to Cups, ML to Oz and the full volume converter.
Gallons to Liters conversion table
Values in liters are rounded to 4 decimal places (more for very small numbers). For any value not listed, type it into the converter above.
| gal | L | gal | L |
|---|---|---|---|
| 1 | 3.7854 | 19 | 71.9228 |
| 2 | 7.5708 | 20 | 75.7082 |
| 3 | 11.3562 | 25 | 94.6353 |
| 4 | 15.1416 | 30 | 113.5624 |
| 5 | 18.9271 | 35 | 132.4894 |
| 6 | 22.7125 | 40 | 151.4165 |
| 7 | 26.4979 | 45 | 170.3435 |
| 8 | 30.2833 | 50 | 189.2706 |
| 9 | 34.0687 | 55 | 208.1976 |
| 10 | 37.8541 | 60 | 227.1247 |
| 11 | 41.6395 | 65 | 246.0518 |
| 12 | 45.4249 | 70 | 264.9788 |
| 13 | 49.2104 | 75 | 283.9059 |
| 14 | 52.9958 | 80 | 302.8329 |
| 15 | 56.7812 | 85 | 321.76 |
| 16 | 60.5666 | 90 | 340.6871 |
| 17 | 64.352 | 95 | 359.6141 |
| 18 | 68.1374 | 100 | 378.5412 |
Gallons to Liters FAQ
How many liters is 5 gal?
5 US gallons is 18.9271 liters: 5 gal × 3.785411784 = 18.9271 L.
How do I convert gallons to liters?
Multiply the value in gallons by 3.785411784. For example, 20 gal × 3.785411784 = 75.7082 L. To convert back, divide the value in liters by 3.785411784 — or use the Liters to Gallons converter.
How many US gallons are in one liter?
One liter is 0.2642 US gallons, because 1 L ÷ 3.785411784 = 0.2642 gal.
What is 20 gallons in liters?
How many liters are in a UK gallon?
An imperial (UK) gallon is exactly 4.54609 L — about 20% more than a US gallon, which is 3.7854 L. If your gallons are imperial, read the UK line shown under the result.