There is a webstie called
Sparkpeople.com that is really neat. It has you fill out a profile and asks you questions about how much you weigh, your height, how active you are, and what your goal weight is (it won't let you choose something unreasonable) and then it gives you a calorie range. It also has a neat option where you can keep track of what you eat and then it figures out the calories for you.
Check it out! I love it.