how many ounces in a glass
While it is going to determine how big a glass as to how much it is. In most cases when someone says your are supposed to drink 6 glasses of water a day, they are talking about an 8 ounce glass. One cup equals 8 ounces. Use that as a comparison. Clarification While it is true that most drinking glasses are larger than 8 ounces, it should be noted that medical recommendations to drink 6 glasses of water every day are based on the contents of six, 8 ounce glass.