Liters to Gallons Converter

liters to US gallons — quick reference

The formula, worked line by line

A US gallon is exactly 3.785411784 liters, so liters into US gallons is a single division by that constant. The number is not a measurement or a best estimate — it falls out of two exact definitions. The US gallon is legally 231 cubic inches, and the inch has been exactly 25.4 mm since the international yard and pound agreement of 1959, so 231 × 2.54³ cubic centimetres gives 3,785.411784 mL exactly.

That means the only rounding on this page happens in the display. It matters at scale: converting a 200-liter drum multiplies whatever error is in your factor by 200, so a divisor rounded to 3.79 shifts the answer by roughly a hundredth of a gallon and a divisor rounded to 4 shifts it by nearly three gallons.

If you need the imperial gallon instead, swap in 4.54609, which has been the exact legal definition in the UK since the Weights and Measures Act 1985.

US gallons = liters ÷ 3.785411784
imperial gallons = liters ÷ 4.54609
50 L ÷ 3.785411784 = 13.21 US gal
price per US gallon = price per liter × 3.785411784

Two rules of thumb and their error budgets. Dividing by four gives 12.50 gallons for 50 liters against the true 13.21, so it reads about five percent low; that is fine for a mental estimate and wrong in the unsafe direction when you are sizing a tank or a heater.

The better mental method is to divide by four and then add a quarter of the result divided by four — or more simply, take a quarter and add six percent. For quarts there is a cleaner shortcut: one liter is 1.0567 US quarts, so liters and quarts are within six percent of each other and a liter carton is very nearly a quart carton.

Volume only, and mind the pints

Two limits worth stating plainly. This converter handles liquid volume only: it does not convert volume into weight, because that needs the density of the specific substance, and it does not touch US dry pints and quarts, which are a separate and larger set used for produce.

And the pint mismatch runs deeper than the gallon one looks. Both systems put 8 pints in a gallon, so the imperial pint inherits the full 20.09 percent gap at 568.26125 mL against the US pint at 473.176473 mL — while the imperial fluid ounce is the smaller of the two ounces, at 28.4130625 mL against 29.5735295625 mL, because 20 of them go into an imperial pint rather than 16.

How to use the liters to gallons converter

Type a liter figure and the US gallon equivalent appears as you type, to two decimal places; Swap reverses the direction without retyping.

Liters land in front of a US reader in a few reliable places: the pump on a trip abroad, the spec sheet for an aquarium, a water heater or a rain barrel, the capacity printed on imported drums and jerrycans, and almost any capacity quoted in a non-US manual.

The conversion itself is one division by an exact constant, 3.785411784, so there is no approximation anywhere in the arithmetic — but there is a trap in the word gallon, and it is the reason this page carries a second table. The gallon this tool uses is the US gallon. The imperial gallon still used in parts of the UK and in Canada is a genuinely different size and it shares the name exactly.

The definitions are worth knowing because they explain the gap rather than just asserting it, and both of them sit in the callout below. Reading a liter figure with the wrong gallon in mind therefore skews the answer by about a fifth in one direction or the other: 50 liters is 13.21 US gallons but only 11.00 imperial gallons, a difference of 2.21 gallons on a single tankful.

Equipment is the other driver, and here the gallon figure is the one that lets you shop. A 200-liter aquarium is 52.83 US gallons, a 50-liter water heater is 13.21 gallons, and a 20-liter jerrycan is 5.28 gallons — worth converting because US stands, filters, heating elements and pump ratings are all sized in gallons. Use the exact figure whenever the number drives a purchase, and note that this tool converts volume only — never volume into weight.

How do you compare fuel priced per liter?

Filling up abroad is the everyday case, and the surprise usually arrives at the register rather than the pump. A 50-liter fill is 13.21 US gallons, so a total that looks enormous in liters is an ordinary tankful. What actually needs converting is the price, not the volume. Convert the unit price by the same 3.785411784 and you find out whether fuel is genuinely dearer where you are or whether it only looks that way in unfamiliar units.

Every liters value, worked out

68 common liters figures each get their own page, with the answer at full precision, the arithmetic, what rounding costs, and the nearest real-world reference point on the scale.

Questions people ask