One teaspoon of sugar weighs 4.2 grams. A tablespoon of sugar weighs around double that. It is recommended that people do not consume more than 25 grams, or about 6 teaspoons, of sugar a day.
It is usual for product labels to list sugar content in grams. However, this does not equate directly to teaspoons of granulated sugar, since it also includes natural sugars, such as from fruit and milk, and added or refined sugars, such as high-fructose corn syrup or evaporated cane juice. The average American consumes around 22 teaspoons, or more than 90 grams, of sugar a day. This equates to 350 calories.