I do track my calories in, and I don't think it's a bad idea. The issue is trying to tally it against what you burned that day. That is an incredibly complicated number to pin down, because there are so many biological variables at play all the time. For example, your base metabolic rate will change over the course of the day, and the sum of that is different each day. Simple things like the foods you eat make a difference too. Eating a 300kilocalorie steak will actually need you to burn for more calories to digest than say a banana. There is variable upon variable in your biochemical pathways that also plays into this as well. Take any calorie expenditure calculation with a very large grain of salt is the summary. As long as you use and in and out tracking as a broad guideline (and not something to dwell on in minutae) that's going to be fine. Watching your results and how they change generally with your intake and exercise is a good way to succeed without getting too wrapped up in things you can't known for certain.