Volume Converter
Convert between millilitres, litres, fluid ounces, cups, pints, quarts, and gallons. Useful for cooking and engineering.
Volume Converter
Enter a value in any unit β see the conversion in all others instantly. All calculations run in your browser.
Quick References
How to Convert Between Cups, Liters, Gallons, and Other Volume Units
You found a British baking recipe that lists milk as 300 mL, but your measuring cups are marked in US cups. Pouring 300 mL into a "1 cup" measure would overfill it by nearly a quarter. Enter 300, select mL, and the converter instantly shows 1.268 US cups, 10.56 fl oz, and every other equivalent. The copy button beside each result means you can paste the right measurement straight into your recipe notes.
The converter covers 11 units from milliliters through cubic meters, including the US and imperial gallons that differ by about 20%. A homebrewer converting a 5-gallon batch recipe to liters (18.93 L) for a metric brewing kit, a nurse converting fluid ounces to milliliters for medication dosing, or a fuel buyer comparing pump prices in liters versus gallons β all get their answer without leaving the page. The quick-reference row at the bottom translates the current value into everyday objects: a teaspoon at 4.93 mL, a wine bottle at 750 mL, a bathtub at 300,000 mL.
Cooking conversions where precision actually matters
A Mary Berry cake recipe calls for 225 g of butter β but your US measuring cup reads volume, not weight. Butter has a density of about 0.911 g/mL, so 225 g equals roughly 247 mL. A US cup is 236.588 mL, so you need just over 1 cup. The volume converter helps you cross-reference: enter 247 mL and see that equals 1.044 US cups, 8.35 US fl oz, or 15.74 metric tablespoons. Getting this right means the difference between a cake that rises and one that collapses.
A pharmacist in the US receives a prescription written in milliliters but the measuring syringe is marked in teaspoons. A 10 mL dose equals exactly 2.029 US teaspoons. For pediatric dosing, where a 0.5 mL error can mean a 10% overdose on a 5 mL dose, the exact conversion matters. The tool converts between mL, tsp, tbsp, and fl oz so the pharmacist can select the closest safe mark on the syringe.
A homebrewer in Canada follows an American recipe calling for 5 US gallons of wort. Converting to liters gives 18.927 L. But the yeast pitching rate is specified per liter, and the malt extract is sold in kilograms per liter. The volume converter bridges the gap: 5 US gal = 18.927 L, which means at 0.75 million cells per mL per degree Plato, the brewer needs roughly 14.2 billion cells for a moderate-gravity ale.
How the Volume Converter Handles Cups, Gallons, and Liters
Every unit in the converter is stored as a multiple of one milliliter. When you enter 2 US gallons, the tool multiplies 2 by 3785.411784 to get 7570.823568 mL, then divides by each target unit's factor. Because all conversions pass through milliliters in a single step, there is no cascade of intermediate rounding. The result for 1 US gallon to imperial gallons is 0.832674 imp gal β not an approximation derived from rounding the individual factors first.
Why US and imperial gallons differ by exactly 20%
The US gallon traces back to the wine gallon defined by Queen Anne in 1707, which was based on the medieval English wine measure of 231 cubic inches. When the British Empire reformed its measures in 1824, the imperial gallon was redefined as the volume of 10 pounds of water at 62Β°F β which works out to approximately 277.42 cubic inches, about 20% larger than the US gallon. The US never adopted the 1824 reform, keeping the older wine gallon. This historical accident means a US gas station selling "a gallon" is selling about 3.785 liters, while a British petrol station sells 4.546 liters per gallon.
US smaller units derive from the gallon by exact factors of 2: 1 gallon = 4 quarts = 8 pints = 16 cups = 128 fluid ounces. The metric equivalents are exact to 6+ decimal places: 1 US cup = 236.5882365 mL, 1 US fl oz = 29.5735295625 mL. The metric units (mL, L, mΒ³) are exact powers of 10. The imperial gallon is exactly 4.54609 liters, making all imperial volume factors exact as well.
The teaspoon-tablespoon-cup hierarchy in US customary
In the US system, volumes follow a clean binary subdivision: 1 cup = 16 tablespoons = 48 teaspoons. A tablespoon is exactly 3 teaspoons, and a cup is exactly 2 tablespoons times 8 (16 tbsp). This is convenient for recipe scaling β doubling a recipe that calls for 1.5 tsp of vanilla means 3 tsp = 1 tbsp exactly. The metric system does not have this hierarchical relationship: a metric tablespoon is 15 mL, a metric teaspoon is 5 mL, and a metric cup is 250 mL β so 1 metric cup = 5 tablespoons, not 16.
The converter's formatting adapts to the magnitude of the result. Cubic meters for a swimming pool (2.5 million mL) display with locale separators and two decimal places. Milliliters for a single teaspoon (4.929 mL) show six decimal places. Very large or very small values switch to scientific notation. This keeps the output readable whether you are measuring a single drop or a tanker load.
Frequently Asked Questions
How many milliliters are in 3 US cups?
Three US cups equals exactly 709.765 mL. One US cup is 236.5882365 mL, and multiplying by 3 gives 709.7647095 mL, which rounds to 709.765 for display. If your recipe calls for 3 cups of milk, you need a measuring container marked to at least 710 mL. Most metric measuring jugs have mL markings every 25 mL, so you would fill to the 700 mL line and add roughly 10 more mL β about two-thirds of a metric tablespoon.
Why is a metric cup 250 mL when a US cup is 236.588 mL?
The metric cup was defined in 1970 by the Canadian government as exactly 250 mL β a round number in the metric system. The US cup traces back to the 19th century and is defined as half a US pint (231 cubic inches), which works out to 236.588 mL. The 13.4 mL difference seems small, but over 8 cups (a common baking quantity) it adds up to 107 mL β nearly half a cup of extra flour if you use a metric cup for a US recipe.
How do I convert a recipe from liters to gallons?
Divide the liter value by 3.78541 for US gallons, or by 4.54609 for imperial gallons. A recipe making 4 liters of soup equals 1.057 US gal or 0.880 imp gal. For quick mental estimates, 4 liters is roughly 1 US gallon β close enough for home cooking. The exact figure matters more when scaling commercial food production, where a 1% error across a 500-gallon batch means 5 gallons of wasted product.
What is the difference between a fluid ounce and a regular ounce?
A fluid ounce measures volume, while a regular ounce measures weight. One US fluid ounce of water weighs approximately 1.043 oz (29.57 g) at room temperature β close to one ounce by weight, which is why the names are confusing. For water and similar liquids, 1 fl oz β 1.04 oz weight. For denser liquids like honey (1.42 g/mL), 1 fl oz weighs about 1.47 oz. This converter handles volume only; for weight conversions, use the weight converter.
Can I use this to calculate fuel costs for a road trip?
Yes, as part of a two-step calculation. If fuel is sold by the liter at $1.85/L and your car consumes 8.5 L/100km, you can use the volume converter to translate between liters and gallons. A 500 km trip uses 42.5 L of fuel. In US gallons that is 11.23 gal. At $1.85/L, the trip costs $78.63. At US prices (around $3.50/gal), the same trip costs $39.30 β demonstrating why fuel economy comparisons between metric and imperial countries can be misleading.