Depending on the chef, the rice portion of the sushi can vary from 20-30 calories or 3~5 grams of carbohydrate. 15 grams of sugar (60 cal) and 10 grams of salt are used to make 100ml of sushi rice vinegar. A less than a third, or 30ml of this is used for a whole cup of rice. A cup of rice will yield about 25 pieces of sushi. One nigiri sushi will contain no more than 0.7 cal from the sugar, or 0.2 grams of carbohydrates.