Volume Converter
Enter a value to instantly convert between volume units.
Volume conversions are most familiar from the kitchen — converting cups to milliliters, or figuring out how many liters are in a gallon of fuel or paint — but they also come up in construction (concrete volumes), science (lab measurements), and everyday shopping (comparing product sizes sold in different units across countries). Because volume units come from both the metric system (milliliters, liters) and several different historical systems (US customary cups and gallons, UK imperial pints and gallons), this is one of the categories where 'the same name' can mean different things depending on where you are.
1 Liter = 0.2642 US Gallon
Key Formulas
Liter → US Gallon
gal = L × 0.264172US Gallon → Liter
L = gal × 3.78541US Cup → Milliliter
mL = cup × 236.588Milliliter → US Cup
cup = mL × 0.00422675Popular Conversions
All Volume Conversions
About Volume Conversions
History & Background
The liter was introduced as part of the original metric system in the 1790s, defined as the volume of one kilogram of pure water — a definition later refined and tied to the cubic decimeter for precision. US customary volume units (cups, quarts, gallons) descend from English units of the same names, but the US and UK versions diverged after American independence: the US retained an older definition of the gallon based on wine measurement (231 cubic inches), while the UK adopted a new, larger imperial gallon in 1824 based on the volume of 10 pounds of water. This split is why a US gallon (3.785 L) and an imperial/UK gallon (4.546 L) differ by about 20% — a single historical decision still affects fuel economy figures, recipe conversions, and product sizes today.
How to Use This Converter
Choose your starting and target units and enter a value to see the converted result instantly. For cooking conversions, be aware that 'cup' measurements default to the US cup (236.6 mL) — if a recipe specifies a metric cup (250 mL) or comes from a country using a different standard, the conversion will differ slightly. See our cooking conversion guides for more on this.
Frequently Asked Questions
Why is a US gallon smaller than a UK (imperial) gallon?
The two countries' definitions diverged in 1824 when the UK standardized its imperial gallon as the volume of 10 pounds of water at a specified temperature, while the US retained an older gallon definition based on wine measurement. The result is that a US gallon (3.785 liters) is about 17% smaller than an imperial gallon (4.546 liters) — a difference that affects fuel economy comparisons, recipe conversions, and any product sold by the gallon across both markets.
Is a fluid ounce the same as an ounce of weight?
No — a fluid ounce measures volume, while a regular ounce measures weight (mass). They're only equivalent for substances with a density close to water's (like most beverages), where one fluid ounce of water weighs approximately one ounce. For denser liquids (honey, oil) or any solid ingredient, a fluid ounce and an ounce by weight are different quantities, which is a common source of confusion in cooking conversions.
How many milliliters are in a teaspoon and tablespoon?
In US measurements, 1 teaspoon = 4.93 mL and 1 tablespoon = 14.79 mL (3 teaspoons). Some countries, notably Australia, use a larger tablespoon (20 mL). For precise baking, especially with small quantities of leavening agents or flavoring, these differences can matter — check which standard a recipe is using if results seem off.
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