For male weight maintenance, easiest rule is your bodyweight (in pounds) x 10. Therefore 150 lbs = 1,500 calories. The caloric intake of any individual is dependent on many factors. Your age, natural resting metabolism, body composition and activity level will all affect your ideal caloric intake. Therefore there is no general rule in determining your caloric intake. The link below provides an estimate based on some of the factors mentioned above.
2200
The average recommended caloric intake for the average 13 year old female is 2106. For a male, it is 2234. These figures are based on weight maintenance with moderate activity. Any question relating to dieting or caloric intake should be discussed with a doctor as there are many factors to consider.
Carbs
By reducing caloric intake, one would lose weight. By increasing caloric intake, you'd gain weight.
exercising four times a day
Caloric intake has a lot to do with the amount of physical activity a person participates in. If someone has a high caloric intake but they don't exercise or move a lot, they will gain weight.
weight maintenance will occur
The ideal caloric intake can't be based on height and weight alone. Activity level (caloric expenditure) must be considered.
BPE
It is important to consider the client's daily caloric intake and their lifestyle.
http://www.babycenter.com/0_nutrition-guidelines-for-young-children_64359.bc
The average calorie intake for a male is between 2000 and 2200 calories.