The number of fluid ounces in a cup can vary depending on the standard of measurement being used. In the United States, a standard cup for liquid measurements is equal to 8 fluid ounces (fl oz). However, in some other countries, such as Canada and the United Kingdom, a standard cup is equal to 8.8 fluid ounces (approximately 250 milliliters).
So, in the US:
1 cup = 8 fluid ounces
And in some other countries:
1 cup = 8.8 fluid ounces
It’s important to be aware of the specific cup measurement being used in your region or the recipe you are following, as using the wrong cup measurement can affect the accuracy of your cooking or baking.