I'd start out between 3200 and 3600 calories a day. I'd split it pretty evenly between protein/carbs/fat. Maybe a little higher on carbs and protein, and make sure you are getting most of your fats from good sources.. Watch this for a couple of week, and see how you're growing. If you think you are gaining too much fat, you can drop the calories a little, and if you aren't gaining, up them. Anything over 3000 calories should let you gain weight, and anything over 3600 will run the risk of putting on quite a bit of fat. Make sure you are giving your muscles enough time to recover between workouts to make the most of the food you are eating. Good luck.