There are 8 fluid ounces in 1 US cup for liquid measurements. For dry ingredients, 1 cup is approximately 4.5 ounces by weight , but this can vary depending on the ingredient's density and how it is packed. The standard US cup equals 8 fluid ounces (volume).

Key Points:

• 1 cup = 8 fluid ounces (for liquids)
• 1 cup = about 4.5 ounces by weight (for dry ingredients)
• 1 cup is approximately 237 milliliters in volume measurement

This difference is important because fluid ounces measure volume, while dry ounces measure weight and differ by ingredient type.