To use a carbohydrate counting chart, calculate 15 grams of carbohydrates for every single carb "choice" or "serving." The existing models for carbohydrate counts pertain to diabetics and the need to control blood glucose. The American Diabetes Association defines one carbohydrate choice as one slice of bread, one small apple and one cup of milk.
A longer list of carbohydrate choices and corresponding serving amounts is available at Diabetes.org. The ADA advises a starting point for carbohydrate ingestion of 45 to 60 grams per meal. According to the ADA carbohydrate chart, that amounts to three servings of carbohydrates: 6 ounces of baked potato, three tortillas or three small pieces of fruit.
It is acceptable to mix carbohydrate choices, providing they do not exceed recommended limits. For example, 1/3 cup of pasta and 1/2 cup of spaghetti sauce are two carbohydrate choices, which allows for a dessert, such as 1/2 cup of light ice cream.
The University of Pittsburgh Medical Center suggests an even higher carbohydrate threshold of 3 to 4 carbohydrate choices per meal for women, 4 to 5 carbohydrate choices per meal for men and 1 to 2 carbohydrate choices as an evening snack. The ADA says that reading nutrition labels is key to translating the carbohydrate counts within packaged foods into acceptable servings.
On a nutrition label, the serving size and the grams of total carbohydrate are crucial for determining how much of the product is a feasible carbohydrate serving. The latest edition of "The Complete Guide to Carb Counting" from the ADA is available at ShopDiabetes.org and Amazon.com, as of 2015.