How many calories should I be eating daily in order to lose weight?

I am 28. I excercise at Bally’s gym 6-7 days a week at 6am. I do the eliptical machine for 40-45 minutes. Then i do 40 sit-ups,30 push ups, and a few other weight machines every morning. But it seems like i am not losing weight..as a matter if fact, sometimes, i feel i am gaining weight.So i want to know what my calorie intake should be in order to lose weight. I weigh 170 lbs and my height is 5’8″.