How much sugar in a can of lemonade?

Anything from 'none at all' to 'far too much'. Since lemons are quite acidic, people tend to put in too much sugar. Factory-made lemonade with no sugar is almost always prominently labelled 'sugar free'. If you need to know, read the label; the calorie count will tell you how much sugar because almost all the calories in lemonade come from sugar. If you are a diabetic, or dieting, the calorie count is what you need to know rather than where the calories came from.