1 gram of carbohydrate provides 4 calories to person
Sugar is also a form or type of carbohydrates, so it also contains 4 calories in its 1 gram. Where as 1 teaspoon of sugar provides 15 calories
I read somewhere there are 9 calories per gram of sugar. I don't recall if those were potential calories, sugar makes you want to eat and there may be less than 9 calories in each gram of sugar, although I believe sugar has the tendency to make you eat twice as many calories, or more than twice, I. E. If you eat something that has 20 grams of sugar we can calculate that it contains 180 calories, in the sense that we will need to ingest more calories to lessen hunger, it may actually only contain 80 calories.
Granulated silver spoon is1 serving 20 grams is 80 Cal so 1 gram is 4 Cal