I'm confused on calories, please help?

I'm 5' 6'' and somewhere around 134 lbs. I lift weights (using dumbells, barbells, physioballs, and some machinery) 3-5 times each week depending on what I have time for and I do sprints on a treadmill where you change the incline and speed twice a week, then run about 3 miles once a week. How many calories do I need to lose fat?