How many calories?

I was wondering how many calories I should eat if I want to lose body fat but gain muscles. I want to eat 2000 calories at least, but I don't want to gain fat, so I was wondering if it's too little or too much. I run 3-5 km every other day + strength, which means I burn about 300-500 calories. So the question is actually: How many calories should I eat on a day I workout? Should I eat 2300 calories on a workout day where I burn 300 calories?