Calculating macros by percentages?

Ok im creating a food for the database and in the nutrition label it only gives me the calories of the food but i want to know the grams of carbs, protein & fat. So the problem is that in the food all the information they give is percentage, so the food is 190 kcal total and it says it is 8% fat, 21 grams carb and 8% protein.... So how do i find out how many grams of fat and protein is that?

Thanks!