How Many Ounces in a Cup?

There are 8 fluid ounces in one US cup. This is one of the most frequently used kitchen conversions, especially for liquids. One fluid ounce is about 29.6 milliliters, so a cup comes to roughly 237 mL.

📏 Fluid Ounces to Cups Chart

⚖️ Is a Fluid Ounce the Same as a Regular Ounce?

No, and this trips up a lot of people. A fluid ounce measures volume while a regular ounce measures weight. They are almost identical for water (1 fl oz of water weighs about 1.04 oz), which is a convenient coincidence. But it falls apart for other liquids. One fluid ounce of honey weighs about 1.5 ounces because honey is much denser than water. One fluid ounce of vegetable oil weighs about 0.96 ounces because oil is lighter.

🥤 How Many Ounces in Common Drink Sizes?

A standard soda can is 12 fluid ounces (1.5 cups). A tall Starbucks coffee is 12 ounces, a grande is 16 ounces (2 cups) and a venti is 20 ounces (2.5 cups). A standard wine glass pour is 5 ounces. A shot glass is 1.5 ounces. These are useful benchmarks if you are trying to track how much liquid you consume in a day.

📐 How Many Ounces in Half a Cup?

4 fluid ounces make half a cup. This comes up constantly in cooking, especially for liquids like broth, milk and oil. Most liquid measuring cups have markings at every 2-ounce increment, so finding the 4-ounce line for half a cup is straightforward. For dry ingredients, its more accurate to use a dedicated half-cup measure rather than eyeballing the line on a liquid measuring cup.

🌍 Are Fluid Ounces the Same in the US and UK?

No. A US fluid ounce is 29.57 mL while an Imperial fluid ounce is 28.41 mL. The US ounce is actually slightly larger, which seems backwards since US cups, pints and gallons are all smaller than their Imperial equivalents. The reason is that the two systems defined their base units differently back in the 1800s and never reconciled.

☕ A Starbucks "Grande" Is Not Actually a Large

Starbucks sizing is deliberately confusing. A "Grande" (16 oz, 2 cups) is actually the medium size. "Tall" (12 oz) is the small, and "Venti" (20 oz) is the large. The names come from Italian, but no Italian coffee shop uses this system. Starbucks originally had only Short (8 oz) and Tall (12 oz). When they added bigger sizes, they moved the names up rather than calling anything "small," because marketing research showed people dislike ordering a "small."