How Many Ounces In A Cup of Coffee? The number of ounces in a cup of coffee can vary depending on the context and the country you're in, but in general, a standard cup of coffee in the United States is typically considered to be 8 fluid ounces. However, when it comes to coffee specifically, there’s a bit of nuance. For example, in the coffee industry, a “cup” of coffee often refers to 6 fluid ounces, which is the standard used by many coffee makers and is based on historical brewing measurements.