How to calculate macronutrients
First, you need to find out your total calories
There are many ways to figure this out, but let's keep it simple.
BODY WEIGHT X 14
Example:140 LBS Female - 140 x 14 = 1960 Calories
1960 is the sustaining calories
SUBTRACT 250-500 Calories to lose weight
ADD 250-500 Calories to gain weight
Example: 1960 - 250 = 1710 Calories
Now, it's time to figure out your macros
1 gram of protein equals 4 calories
Body weight = 1 gram of protein
Example: 140 LBS = 140 GMS of protein
1 gram of fats equals 9 calories
Let's keep this simple aswell. Fats will be 25% of your calories
Example: 1710 x .25 = 427.5
Divide that number by 9
42.7/9 = 47.5 grams of fat
1 gram of carbs is 4 calories
Remainder calories will be carbs
Example: 140 protein x 4 = 560 calories
47.5 fats x 9 = 427.5
560 + 427.5 = 987.5 calories
Total calories 1710 - 987.5 = 722.5 carb calories
722.5 x .25 = 180.6 carbs
PROTEIN = 140 grams
FATS = 48 grams
CARBS = 180 carbs
A FEW EXAMPLES
To lose body fats - lower carbs and raise protein.
To gain muscle - lower fats raise carbs.
Jusat make sure the total macros equal your total calories.
This is just a simplified way to calculate macros.
If you have specific goals, there are more in depths way to calculate them.
WHY WE KEEP TRACK OF OUR MACRONUTRIENTS?
Those who wrote down their food daily lost twice as much weight
as those who did not write down their food (Study from Bodybuilding.com)