Convert gallons to liters
Convert gallons to liters instantly. 1 gal = 3.785412 L. Formula, worked examples and a quick reference table.
Last updated
One us gallon equals 3.785412 liters. To convert any number of us gallons to liters, multiply by 3.78541178.
The converter above works in both directions and updates as you type. Below you will find the formula, a worked example and a reference table of common values.
Volume is the category where the US and imperial systems diverge most damagingly. Gallons, quarts, pints and fluid ounces all exist in two sizes that differ by up to 20%, and nothing in the name warns you which one a figure uses. Recipes, fuel economy figures and container capacities all cross borders regularly, so it is worth checking which system a source is using before converting rather than after.
gallons to liters formula
To go the other way, use us gallon = liter ÷ 3.78541178.
About these units
A US gallon is 231 cubic inches, about 3.785 litres. It is noticeably smaller than the imperial gallon, which is a frequent source of fuel-economy confusion.
A litre is exactly one cubic decimetre, or 1,000 cubic centimetres. One litre of water weighs almost exactly one kilogram, which is not a coincidence.
US Gallon is also written gallons, gals and us gal. Liter is also written litre, litres, liters and ltr.
Sources
- National Bureau of Standards, "Refinement of Values for the Yard and the Pound", Federal Register, 1 July 1959 — the international yard as exactly 0.9144 m and the avoirdupois pound as exactly 0.45359237 kg.
- NIST Special Publication 811, Guide for the Use of the International System of Units (SI), 2008 edition — conversion factors for units outside the SI.
gallons to liters conversion table
| US Gallon | Liter |
|---|---|
| 1 gal | 3.7854 L |
| 2 gal | 7.5708 L |
| 3 gal | 11.3562 L |
| 5 gal | 18.9271 L |
| 10 gal | 37.8541 L |
| 20 gal | 75.7082 L |
| 25 gal | 94.6353 L |
| 50 gal | 189.2706 L |
| 100 gal | 378.5412 L |
| 250 gal | 946.3529 L |
| 500 gal | 1,892.7059 L |
| 1,000 gal | 3,785.4118 L |
Frequently asked questions
How many liters are in a us gallon? +
There are 3.785412 liters in one us gallon.
What is 10 gal in L? +
10 gal equals 37.8541 L. Multiply 10 by 3.78541178.
How do I convert liter back to us gallon? +
Use us gallon = liter ÷ 3.78541178. The converter above handles both directions, or see our dedicated liters to gallons page.
How accurate is this us gallon to liter conversion? +
The factor used is 3.785411784, carried at full double precision. Where a unit has an exact legal definition the factor is exact rather than approximate. Rounding is applied only to the displayed result, so the answer is never a calculation done on an already-rounded number.
Is there a quick way to estimate gal to L in my head? +
Multiply by 15 and divide by 4. That approximates the true factor of 3.785412 to within 0.9355%, which is close enough for a mental estimate.