Volume Converter

The Problem with Volume Units: US vs UK vs Metric

Volume is the unit category with the most dangerous false friends — units that share names but have completely different sizes depending on which side of the Atlantic you are on. A US gallon is 3.785 litres. A UK (Imperial) gallon is 4.546 litres — about 20% larger. A US pint is 473 ml. A UK pint is 568 ml. A US fluid ounce is 29.57 ml; a UK fluid ounce is 28.41 ml. A US cup is 240 ml; a UK cup is 250 ml. If you are following a recipe, filling a fuel tank, or calculating a chemical dosage, using the wrong gallon can produce results that are significantly wrong — not just slightly off. This converter makes the US/UK distinction explicit for every relevant unit, and supports 15 units total so you can work across metric, imperial, and US customary systems without confusion.

All 15 Supported Volume Units

• Cubic Metre (m³): Engineering and construction — concrete pours, water tanks, shipping containers
• Litre (L): The universal everyday liquid measure — beverages, fuel, water
• Millilitre (ml): Cooking, medicine, lab work; 1 ml = 1 cm³ exactly
• Centilitre (cl): European wine and spirits serving measures; 1 bottle = 75 cl
• US Gallon (gal): American fuel, milk jugs, pool chemicals — 3.78541 L
• UK Gallon (UK gal): British and Commonwealth fuel and bulk liquid — 4.54609 L
• US Quart (qt): Motor oil, paint in the US; 1 US qt = 0.946353 L
• US Pint (pt): US beer, deli containers, berries; 473 ml (vs UK pint 568 ml)
• UK Pint (UK pt): British pub measure for beer; 568 ml — a UK pint is 20% larger than a US pint
• US Cup (cup): American cooking measurement; 240 ml
• US Fluid Ounce (fl oz): US medicine bottles, nutrition labels; 29.5735 ml
• Tablespoon (tbsp): Cooking — US definition is 14.787 ml (≈ 3 teaspoons)
• Teaspoon (tsp): The smallest common cooking measure; US 4.929 ml
• Cubic Inch (in³): Engine displacement in American automotive, HVAC duct volume
• Cubic Foot (ft³): Refrigerator capacity, room air volume, concrete in US construction

Cooking Conversions: The Most Common Reason People Use This

Recipes are the single biggest driver of volume conversion searches. An American recipe that calls for "1 cup of flour" means 240 ml to a US baker but might be interpreted as 250 ml by a British or Australian baker — a 4% discrepancy that is large enough to affect baked goods. A recipe using "2 tablespoons" refers to 30 ml in the US, but some UK recipes use a 15 ml tablespoon and some a 20 ml tablespoon. This tool uses the standard US definitions throughout, which aligns with the most common online recipe sources. For precise cooking conversions between cups, tablespoons, teaspoons, and millilitres, also try the Cooking Measurements Converter which includes dry and wet ingredient-specific conversions. For the weight of ingredients (grams, ounces) alongside volume, use the Weight Converter.

Fuel and Automotive Volume Conversions

Fuel economy and tank volume are two areas where getting the unit right matters financially. A US mpg figure is based on the US gallon (3.785 L), while a UK mpg figure uses the Imperial gallon (4.546 L). A vehicle rated at 30 mpg (US) achieves 36 mpg (UK) using the exact same amount of fuel — the difference is entirely in the gallon size, not the car's efficiency. Similarly, a "20 gallon" fuel tank listed by a US manufacturer holds 75.7 litres, while a "20 gallon" tank from a UK spec would hold 90.9 litres. If you are comparing fuel costs, rental car fuel fees, or boat fuel range across different countries, always check which gallon definition applies. This converter makes both available so you never have to guess.

Key Volume Conversion Reference

• 1 US Gallon = 3.78541 L = 128 US fl oz = 4 US qt = 8 US pt
• 1 UK Gallon = 4.54609 L = 160 UK fl oz = 4 UK qt = 8 UK pt
• 1 US Pint = 473.176 ml  |  1 UK Pint = 568.261 ml
• 1 US Cup = 240 ml  |  1 US Tablespoon = 14.787 ml
• 1 Litre = 1,000 ml = 0.264172 US gal = 0.219969 UK gal
• 1 ft³ = 28.3168 L = 7.48052 US gal