A bottle of Coca-Cola used to be six fluid ounces (about 170 ml), and a McDonald's single serving was once about seven fluid ounces. Maybe nobody drinks half o

A bottle of Coca-Cola used to be six fluid ounces (about 170 ml), and a McDonald's single serving was once about seven fluid ounces. Maybe nobody drinks half of a modern 500ml bottle, but people certainly used to think of less than half of that as a single serving.