Volume Converter: Liters, Gallons, Cups, Pints
Convert between metric and imperial volume units instantly. Supports milliliters, liters, cubic meters, gallons, quarts, pints, cups, and fluid ounces — both US and Imperial. Calculate the volume of any shape with our Volume Calculator, or convert cooking measurements with the Cooking Converter.
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How it works
This converter uses exact mathematical ratios to translate between volume units. Metric units scale by powers of ten: 1 cubic meter = 1,000 liters = 1,000,000 milliliters. US and Imperial units share similar names but differ in size: 1 US gallon = 3.785 liters (128 US fl oz) while 1 Imperial gallon = 4.546 liters (160 Imperial fl oz). US pints hold 473 ml (16 fl oz) versus Imperial pints at 568 ml (20 fl oz).
Enter a value in either field and the converter instantly calculates the result. Use the swap button to reverse the conversion direction. The quick reference table and all-to-all matrix provide common values at a glance.
How Volume Conversion Works
Volume conversion translates the capacity of a three-dimensional space from one unit to another. The metric system scales neatly: 1 liter equals 1,000 milliliters, and 1 cubic meter equals 1,000 liters. Imperial and US customary units are less uniform and, critically, differ from each other. A US gallon is 3.78541 liters while a UK (Imperial) gallon is 4.54609 liters — a difference of about 20 percent. The same discrepancy applies to pints, quarts, and fluid ounces. Always specify whether you mean US or Imperial when working with these units.
Common Volume Conversions
The most frequently searched volume conversions are liters to gallons (fuel, beverages), milliliters to fluid ounces (cooking, cosmetics), and cups to milliliters (recipes). Other popular conversions include pints to liters (beer, milk), quarts to liters (motor oil), and cubic meters to liters (aquariums, pools). In cooking, US cups (237 ml), tablespoons (14.8 ml), and teaspoons (4.9 ml) are different from their UK and Australian counterparts. For beverages, knowing that a standard US can is 355 ml (12 fl oz) and a UK pint is 568 ml helps with everyday comparisons.
When You Need Volume Conversion
Volume conversion is essential for international cooking and baking (US cups vs. metric milliliters), automotive maintenance (engine oil capacity in quarts vs. liters), fuel calculations (gallons vs. liters at gas stations), beverage and food packaging (fluid ounces vs. milliliters), aquarium and pool sizing (gallons vs. liters for water treatment), and shipping (cubic meters for freight). Travelers renting cars abroad need to understand fuel volumes when the pump displays liters instead of gallons, or vice versa.
US vs. Imperial Volume Units
A common source of confusion is that US customary and British Imperial volume units share names but have different sizes. The US fluid ounce is 29.5735 ml while the Imperial fluid ounce is 28.4131 ml. However, a US pint has 16 fluid ounces (473 ml) while an Imperial pint has 20 fluid ounces (568 ml), making the Imperial pint about 20 percent larger. US and Imperial gallons, quarts, and cups all differ similarly. This distinction matters for recipes, fuel economy comparisons, and product labels. When in doubt, specify "US" or "Imperial" alongside the unit name.
Tips for Accurate Volume Conversion
Always clarify whether a recipe or specification uses US or Imperial measurements. When converting between metric and US units, use 1 US gallon = 3.785 liters and 1 liter = 33.814 US fluid ounces. For cooking, measuring by weight (grams) is more accurate than by volume, especially for dry ingredients like flour whose volume varies with packing. When filling containers, remember that nominal capacity and actual fill volume may differ. Liquid and dry measuring cups in the US have the same volume (237 ml) but are designed differently for accuracy.
Practical Examples
A 2-liter bottle of soda equals 67.6 US fluid ounces or about 0.528 US gallons. A standard US bathtub holds approximately 300 liters (80 gallons). A swimming pool of 50,000 liters equals about 13,209 US gallons. A typical car fuel tank of 50 liters is 13.2 US gallons. A UK pint of beer (568 ml) is noticeably larger than a US pint (473 ml). A recipe calling for 1 US cup of milk means 237 ml, not 250 ml.
FAQ
- How do I convert liters to gallons?
- Divide the liter value by 3.78541 to get US gallons, or by 4.54609 to get UK (Imperial) gallons. For example, 10 liters / 3.78541 = 2.642 US gallons. The US gallon and UK gallon are different: 1 US gallon = 3.785 liters, 1 UK gallon = 4.546 liters. Always specify which gallon you mean to avoid a 20 percent error.
- How many milliliters are in a cup?
- It depends on the country. A US customary cup is 236.588 ml (commonly rounded to 237 ml). A US legal cup (used on nutrition labels) is exactly 240 ml. A metric cup (used in Australia, New Zealand) is exactly 250 ml. A UK cup is 284.131 ml. When following recipes, check whether the source is American, Australian, or British to use the correct cup size.
- What is the difference between US and Imperial gallons?
- A US gallon is 3.78541 liters (128 US fluid ounces), while an Imperial (UK) gallon is 4.54609 liters (160 Imperial fluid ounces). The Imperial gallon is about 20 percent larger. This means fuel economy figures differ: 30 MPG (US) equals about 36 MPG (Imperial). The discrepancy comes from different historical definitions. Canada uses liters for fuel, avoiding the confusion entirely.
- How do I convert fluid ounces to milliliters?
- Multiply US fluid ounces by 29.5735 to get milliliters. Multiply Imperial (UK) fluid ounces by 28.4131 for milliliters. For example, 8 US fl oz x 29.5735 = 236.59 ml (one US cup). The US fluid ounce is slightly larger than the Imperial fluid ounce, but a US pint has fewer of them (16 vs. 20), making the US pint smaller overall.
- How many liters are in a cubic meter?
- One cubic meter contains exactly 1,000 liters. This is because 1 liter equals 1 cubic decimeter (0.001 m3). To convert cubic meters to liters, multiply by 1,000. A standard bathtub holds about 0.3 m3 (300 liters), and a medium swimming pool might hold 50 m3 (50,000 liters). One cubic centimeter (cc or cm3) equals exactly 1 milliliter.
- How do I convert pints between US and UK measurements?
- A US pint is 473.176 ml (16 US fluid ounces), while a UK Imperial pint is 568.261 ml (20 Imperial fluid ounces). The UK pint is about 20 percent larger. This is why a "pint of beer" is a different volume in an American bar versus a British pub. To convert: 1 UK pint = 1.201 US pints. In metric countries, a "pint" is sometimes informally used for 500 ml.
- How many cups are in a liter?
- One liter equals approximately 4.227 US cups, 4.167 US legal cups, 4.00 metric cups, or 3.52 UK cups. For practical cooking purposes, 1 liter is close to 4 metric cups (1,000 ml / 250 ml). In the US, 1 liter equals about 4 and a quarter cups. These differences matter when scaling recipes from different countries.
- How do I calculate fuel tank capacity in different units?
- Common car fuel tanks range from 40-70 liters (10.6-18.5 US gallons or 8.8-15.4 UK gallons). To convert: liters to US gallons divide by 3.785, liters to UK gallons divide by 4.546. A typical 50-liter tank holds 13.2 US gallons or 11.0 UK gallons. Fuel economy is usually quoted in MPG (US or UK) or liters per 100 km.
- What is the difference between a quart and a liter?
- A US liquid quart is 946.353 ml, which is slightly less than a liter (1,000 ml). An Imperial quart is 1,136.52 ml, which is about 13.6 percent larger than a liter. A US quart equals exactly one-quarter of a US gallon. For motor oil, the most common container size is 1 US quart (946 ml), while in metric countries it is 1 liter.
- How do I convert tablespoons and teaspoons to milliliters?
- A US tablespoon is 14.787 ml (commonly rounded to 15 ml). A US teaspoon is 4.929 ml (rounded to 5 ml). An Australian tablespoon is larger at 20 ml. A UK tablespoon is 17.758 ml (though many UK recipes now use the 15 ml metric tablespoon). There are 3 teaspoons in 1 tablespoon. For medication, always use the exact milliliter dosage, not kitchen spoons.
- How much water should I drink per day in liters vs. glasses?
- Common recommendations suggest about 2 liters (8 US cups or about 68 US fluid ounces) of water per day, though needs vary by body weight, activity, and climate. A standard US glass of water is 8 fluid ounces (237 ml). A European glass is typically 200-250 ml. The "8 glasses a day" rule equals about 1.9 liters. Actual fluid needs may be higher and include water from food.
- How do I calculate aquarium volume in liters and gallons?
- Measure the internal dimensions in centimeters, then multiply length x width x height to get cubic centimeters. Divide by 1,000 to get liters. For gallons, divide liters by 3.785 (US) or 4.546 (UK). For example, a 60 x 30 x 40 cm tank = 72,000 cm3 = 72 liters = 19.0 US gallons. Account for substrate, decorations, and incomplete filling when calculating usable water volume.
- What is a barrel and how many liters does it hold?
- A US oil barrel is 42 US gallons or exactly 158.987 liters. A US beer barrel is 31 US gallons (117.35 liters). A UK beer barrel is 36 Imperial gallons (163.66 liters). The oil barrel became the global standard for crude oil pricing. When news reports say "oil is $80 per barrel," they mean 42 US gallons or about 159 liters of crude oil.
- What is the difference between cc and ml?
- One cubic centimeter (cc or cm3) is exactly equal to one milliliter (ml). They are different names for the same volume. The term "cc" is common in medicine (injection volumes, engine displacement) and engineering, while "ml" is standard in cooking, beverages, and chemistry. A 1,600 cc engine has a displacement of 1,600 ml or 1.6 liters.
- What is the difference between a fluid ounce and a weight ounce?
- A fluid ounce measures volume, while an ounce (avoirdupois) measures weight. For water, they are nearly equivalent: 1 US fluid ounce of water weighs about 1.043 avoirdupois ounces (29.57 ml weighs 29.57 grams, and 1 weight ounce is 28.35 grams). For other liquids, the relationship changes with density. Honey is denser, so 1 fluid ounce of honey weighs about 1.5 weight ounces.
- How do I convert pool volume from gallons to liters for chemical treatment?
- Multiply US gallons by 3.785 to get liters. A typical residential pool holds 40,000-80,000 liters (10,500-21,000 US gallons). Chemical dosing instructions usually specify amounts per 10,000 gallons or per 1,000 liters. To convert dosage: if a product says "add 200 grams per 10,000 gallons," the metric equivalent is about 53 grams per 10,000 liters (since 10,000 US gallons = 37,854 liters).