conversions
How Many Ounces in a Cup
Last updated: May 31, 2026
Written by Blake Boege
An ounces-in-a-cup conversion page provides liquid volume and dry weight equivalents between cups and ounces. In the US Customary system, a standard cup holds exactly 8 fluid ounces. In the British Imperial system, a cup holds exactly 10 Imperial fluid ounces (approx. 8.8 US fluid ounces). For dry ingredients, the weight in ounces depends on the ingredient's density.
Convert between cups and fluid or dry ounces instantly. Learn why standard cups differ from legal and Imperial sizes, and review dry weight conversions.
Quick Answer
Find out exactly how many ounces are in a standard cup (8 fluid ounces) and convert cups to ounces instantly.
How Many Ounces in a Cup?
There are 8 fluid ounces in a standard US cup.
For dry ingredients, the weight in ounces depends on the density of the ingredient. A baseline standard reference is 8 weight ounces per cup.
Cup Measurement Standard
Formula: 1 Cup = 8.000 fluid ounces (US Customary Fl Oz)
US Customary Cups to Ounces Table
| Cups (c) | Fluid Ounces (fl oz) |
|---|---|
| 1/8 cup | 1 fl oz |
| 1/4 cup | 2 fl oz |
| 1/3 cup | 2.67 fl oz |
| 1/2 cup | 4 fl oz |
| 2/3 cup | 5.33 fl oz |
| 3/4 cup | 6 fl oz |
| 1 cup | 8 fl oz |
| 2 cups | 16 fl oz |
| 4 cups (1 Quart) | 32 fl oz |
Examples
1/2 Cup (US)
4 fl oz
1 Cup (US)
8 fl oz
2 Cups (US)
16 fl oz
How it works
In home baking and cooking, a standard US Customary cup contains exactly 8 fluid ounces:
Standard Liquid Conversion
1 Cup = 8 fl oz
Conversion Formula
Multiply the number of cups by 8 to get fluid ounces. Divide ounces by 8 to get cups.
Fluid Ounces vs. Dry Ounces (Weight)
One of the biggest pitfalls in kitchen measurements is treating volume ounces and weight ounces as interchangeable.
While 1 cup of water happens to weigh exactly 8 dry ounces (giving rise to the old saying "a pint"s a pound the world around"), this rule fails for other ingredients:
- 1 cup of all-purpose flour weighs about 4.2 ounces.
- 1 cup of granulated white sugar weighs about 7.1 ounces.
- 1 cup of honey weighs about 12 ounces.
For dry baking ingredients, always measure by weight (dry ounces or grams) using a scale for absolute accuracy.
US Customary vs. Legal vs. Imperial Cup Sizes
Different regions use different cup capacities, which changes the number of fluid ounces they hold:
- US Customary Cup: Standard recipe size in America, equivalent to 8 US fluid ounces (approx. 236.59 mL).
- US Legal Cup: Used on food nutrition labels in the US, defined as exactly 240 mL (equivalent to approx. 8.12 fluid ounces).
- Imperial Cup (UK): Used in older British recipes, defined as 10 Imperial fluid ounces, which equals approx. 8.80 US fluid ounces (284.13 mL).
- Metric Cup: Used in Australia, New Zealand, Canada, and modern British recipes, defined as exactly 250 mL (approx. 8.45 US fluid ounces).
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Frequently asked questions
There are exactly 4 fluid ounces in a half cup (US Customary) or 4 dry ounces (standard baseline).
There are exactly 2 fluid ounces in a quarter cup (US Customary) or 2 dry ounces.
Fluid ounces (fl oz) measure volume (the physical space a substance occupies), while dry ounces (oz) measure weight (force of gravity). Fluid ounces are measured with measuring cups, and dry ounces are measured on a kitchen scale.
A standard kitchen measuring cup holds 8 US fluid ounces. However, coffee maker manufacturers historically define a single cup of coffee as 5 or 6 fluid ounces. This represents the typical size of a porcelain teacup rather than a full mug.
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