1 gram of Protein = 4 calories
1 gram of Carbohydrates = 4 calories
1 gram of Fat = 9 calories
Here is another basic mass building formula..
The basic formula to start is 16 calories per pound of bodyweight. For example, a 150 lb man should start with 2,400 calories a day. These calories should be divided up between 5-6 meals a day. After the first couple weeks if you are not gaining weight, you should add 500 calories a day. If after a couple more weeks and no weight is gained, add another 500 calories per day.
Also the ratio of the macronutrients as a general guideline are as follows..
Protein - 1 - 1.5 grams per pound of bodyweight
Carbohydrates - 2-3 grams per pound of bodyweight
Fats - .3 -.4 grams per pound of bodyweight
For a working example, I will use the same 150 lb man. This formula works for every size person, no matter what the weight.
This man would need 2400 calories daily to start gaining weight.
His protein content in grams and total calories with 1 gram per lb of bodyweight..
Protein Requirements at 1 gram per pound of bodyweight..
150 grams would be 600 calories
Carbohydrates at 2 grams per pound of bodyweight
300 grams would be 1200 calories
Fats at .3 grams per pound of bodyweight
45 grams would be 405 calories
Total Calories... 2205 calories.
The extra calories he needed to gain should come from protein and carbs.
At the high end of the formula, his intake would be as follows:
Protein at 1.5 grams per pound of bodyweight..
225 grams at 900 calories
Carbs at 3 grams per pound of bodyweight..
450 grams at 1800 calories
Fats at .4 grams per pound of bodyweight..
60 grams at 540 calories
Total Calories.. 3240 calories
A person at the high end would definitely exceed his required calorie intake. Falling in the middle is also a good range to be in. I hope this example helps some people with the proper amount.