1 L = 0.264172 gal
About volume units
Volume measures how much space a liquid or bulk material fills. This page includes milliliters, liters, US and UK gallons, US fluid ounces and US cups.
In short
One US gallon is about 3.785 liters; one UK (imperial) gallon is about 4.546 liters. One US cup is about 236.6 milliliters.
Cooking measures
US cups and fluid ounces dominate American recipes; most other kitchens use milliliters. 1 US cup ≈ 237 mL; 1 US fl oz ≈ 29.57 mL. If a recipe says “cup” without a country, assume US unless the source is clearly imperial UK.
Fuel & tanks
Fuel economy and tank size are quoted in liters or US gallons. 50 L ≈ 13.2 US gal. UK gallons are larger (≈ 4.55 L), so never mix “gallon” types when comparing mpg or L/100 km figures.
Drinking water
Bottles and coolers are labeled in mL or liters almost everywhere. A “gallon jug” in the US is about 3.79 L. Daily water-intake tips online often switch units—convert the tip into the bottle size you actually own.
Aquariums
Tank volume drives heater, filter and stocking choices. A 20 US gallon tank holds about 76 L. Manufacturers may round; measure length × width × water height when precision matters, then convert to the unit on the equipment chart.
Beer & wine
Pints, bottles and kegs mix metric and customary sizes. A US pint is 16 US fl oz (≈ 473 mL); an imperial pint is larger (≈ 568 mL). Wine bottles are usually 750 mL—about 25.4 US fl oz—regardless of the label language.