Calorie Formula's - Fat: 1gm = 9 calories, Carbohydrates: 1gm = 4 calories, Protein: 1gm = 4calories, Alcohol: 1gm =7 calories
"That means if you know how many grams of each one are in a food, you can calculate the total calories. You would multiply the number of grams by the number of calories in a gram of that food component.
For example, on the nutrition label... if a serving of potato chips (about 20 chips) has 10 grams of fat, the answer is 90 calories. Because 10 grams x 9 (Formula) calories per gram = 90".
Estimated Calories For those Who Are Not Physically Active..http://www.choosemyplate.gov/weight-management-calories/calories/empty-calories-amount.html