Here is a breakdown of the formula in this calculator
 
High Carb Days
Carbs- Body weight in kg x 5 (doesn't include carbs from fiber)
Protein- 1g per pound body weight
Fats- Body weight in kg x .5
 
Medium Carb Days
Carbs- Body weight in kg x 3 (doesn't include carbs from fiber)
Protein- 1g per pound body weight
Fats- Body weigth in kg x .75
 
Low Carb Days
Carbs- Body weight in kg x 1.5 (doesn't include carbs from fiber)
Protein- 1g per pound body weight
Fats- Body weight in kg x 1
 
NO Carb Days
Carbs- 0 (doesn't include carbs from fiber)
Protein- 1g per pound body weight
Fats- Body weight in kg x 1