Convert fluid ounces (fl oz) to cups and back. US and imperial systems, fraction display, cup visualization, and fraction-to-ounce reference table.
A US cup holds 8 fluid ounces, while an imperial cup holds 10 imperial fluid ounces. That difference is small enough to look harmless and large enough to matter in recipes, drink mixing, and food production. It also means the same bottle or measuring cup can produce different-looking answers depending on whether the source recipe is written for the US or UK kitchen standard, so the unit system needs to stay visible instead of being assumed.
This converter handles both systems and shows cups as decimals and fractions, along with tablespoons, teaspoons, milliliters, pints, and quarts. The fraction display is useful because many kitchen tasks need answers like 1/4 cup, 1/3 cup, or 1 1/2 cups rather than a decimal alone. It also helps when you are scaling a recipe up or down and want the result to stay in measuring-cup language instead of forcing you to convert every step by hand.
Use it when a bottle, recipe, or measuring cup gives fluid ounces but the next step in the kitchen is framed in cups. The presets and companion units make it easier to keep portion sizes, baking ratios, and serving counts consistent.
This is one of the most common kitchen conversions, but it becomes error-prone as soon as recipes cross US and imperial measurements. The page gives the answer in the cup formats cooks actually use and keeps the supporting units visible, which is useful when the next step is a tablespoon or teaspoon fraction rather than a decimal. It is also a quick check when a label uses fluid ounces but the recipe writer expects the result to be written as cups and fractions.
US: 1 cup = 8 fl oz | Imperial: 1 cup = 10 fl oz cups = fl oz ÷ oz-per-cup tbsp = fl oz × 2 | tsp = fl oz × 6
Result: 1.5 cups = 1 ½ cups
12 fl oz ÷ 8 = 1.5 US cups. That's equivalent to a standard soda can (12 fl oz = 355 mL).
A US legal cup (used on nutrition labels) is 240 mL. A US customary cup is 236.588 mL. An imperial cup is 284.131 mL. A metric cup is 250 mL. When a recipe simply says "1 cup," you need to know which country it came from to measure correctly.
Fluid ounces (fl oz) measure volume. Weight ounces (oz) measure mass. For water, 1 fl oz ≈ 1 oz by weight. For denser liquids like honey, 1 fl oz weighs more than 1 oz. For lighter liquids like oil, it weighs less. Always check whether a recipe means fluid ounces or ounces by weight.
US standard serving sizes are defined in fluid ounces: a serving of juice is 8 fl oz (1 cup), a serving of wine is 5 fl oz, and a serving of beer is 12 fl oz. Understanding ounce-to-cup conversions helps with portion control and nutrition tracking.
8 US fluid ounces. That is the standard cup measure used in most US recipes and measuring cup sets.
10 imperial fluid ounces. Imperial cups are larger than US cups, so the same recipe can look different if the source uses UK measurements.
4 US cups. If the bottle is being measured in imperial cups, the answer will be different because the cup size changes.
No, 6 fl oz is ¾ cup in the US system. A full US cup is 8 fl oz, so 6 fl oz is short by 2 fl oz.
Some older recipes use a coffee-cup or teacup measure rather than the standard modern US cup. That shorthand is common in older cookbooks, but it is not the same as a modern measuring cup.
⅓ US cup = 2.67 fl oz. That is also about 5⅓ tablespoons, which can be easier to measure if you do not have a marked cup.