oz to Cups Converter

1 cup (US) = 8 fl oz = 16 tbsp = 48 tsp = 240 ml (label-rounded; the exact value is 236.588 ml).

1 cup (UK) = 10 fl oz = 284 ml.

1 cup (metric / Australian) = 250 ml ≈ 8.45 US fl oz.

1 pint (US) = 16 fl oz = 2 cups. 1 quart (US) = 32 fl oz = 4 cups. 1 gallon (US) = 128 fl oz = 16 cups.

1 stick of butter (US) = ½ cup = 4 oz by weight = 8 tbsp.

1 US fluid ounce = 29.5735 ml — close enough to 30 ml for everyday cooking but not for pharmacy or lab work.

The US fluid ounce was defined from the wine gallon (231 in³) and equals 29.5735 ml. The UK fluid ounce was defined from the Imperial gallon (4.546 liters) and equals 28.4131 ml. So a US fl oz is actually slightly larger than a UK fl oz — but a UK cup contains 10 UK ounces, while a US cup contains only 8 US ounces, so a UK cup ends up larger overall (284 ml vs 237 ml).

For most baking, the difference is invisible — a teaspoon of vanilla extract is a teaspoon. For yield-sensitive recipes (custards, bread doughs, candy), the 47-ml gap between a US and UK cup of liquid is enough to throw hydration off and produce a noticeably different result. When following a British cookbook, weigh ingredients in grams if at all possible; weight is the only conversion that is the same on both sides of the Atlantic.

An 'ounce' on a US nutrition label or recipe can be either fluid ounces (volume) or ounces (weight). 8 fl oz of milk is one cup. 8 oz of flour is 1¾ cups. 8 oz of sugar is about 1 cup. 8 oz of cocoa powder is closer to 2¼ cups because cocoa is very low density.

This is why professional bakers weigh everything. A cup of flour scooped firmly from the bag can weigh 150 g; the same cup spooned and leveled weighs 125 g — a 20% difference that ruins delicate pastries.

For ingredient-aware conversions between volume and weight, use our Cooking Conversions tool, which knows the density of flour, sugar, honey, oil, and dozens of other staples.

When doubling a recipe, do not double anything that already saturates the dish — salt, baking powder, vanilla, hot sauce. These follow a curve, not a line: doubling the dish requires only about 1.5× the salt and 1.25× the leavening.

Cake batters do not scale linearly past 1.5×. The wider the pan, the longer the bake; the deeper the pan, the more the center sinks. Splitting a doubled batter across two identical pans and baking simultaneously is almost always better than baking one giant pan.

Liquid measurements are most accurate when read at eye level with a clear measuring cup on a flat counter. Dry measurements should be spooned into the cup and leveled with a straight edge, never scooped directly from the bag (scooping packs more in and adds 15-20%).

Weight beats volume for every ingredient that compacts. A digital kitchen scale that reads in grams costs about $15 and is the single biggest accuracy upgrade for serious baking — every professional recipe and most modern home recipes from the UK, Europe, and Australia are written in grams for exactly this reason.