To decide how much you need in fats, proteins and carbohydrates each day, first you need to discover how many calories you need to consume each day. To figure that out try this equation.
If you are a woman, here's the formula to find out the exact calories you personally need (Basic Metabolic rate or BMR)to maintain your current weight while sleeping.
655+(4.3x weight in pounds) + (4.7 x Height in inches)-(4.7x age in years)=BMR
Now calculate your activity. If you're trying to lose weight, calculate using the sedentary rate: BMR x 0.20= Add this number you get to your BMR and you will have the calorie intake you need to maintain your current weight.
Second you will need to figure out what calorie intake should be taken in each of these categories. for fats multiply it by 0.4, for proteins multiply it by 0.3 for carbohydrates multiply it by 0.3. To check to see if you multiplied right, add all your calories together. You should come up with your total caloric intake.
Now that you know how many calories need to be eaten each day in fats, proteins, and carbohydrate you can figure out how many grams you will need by dividing the calories by 4 for proteins and carbohydrates and 9 for fats.