There are some of my favorite nutrition and calorie calculator tools.
My Food Pyramid – http://www.mypyramid.gov/
This site is the official food pyramid site by the US government and if you want to get the most out of the site then you need to register. This can seem like a pain but it is worth the hassle. The reason for registration is it keeps record of all of the food you have entered over time and it tracks your progression. It also gives you the option to enter in daily exercise and it will then estimate for you the amount of calories burned off during that exercise. Since this site gives you the option to enter a goal the site will suggest to you what it takes to get to your goal. It will also point you in the right direction to get closer to a healthy body mass index (BMI) whether that means eat more or less calories.
Nutritional Analysis Tool 2.0 – http://nat.illinois.edu/mainnat.html
This tool was created by the University of Illinois. It doesn’t require registration but it also doesn’t keep track of your data in the same way that the food pyramid site does. It is a nice quick reference calculator for computing calories for one meal at a time.
WolframAlpha – http://www.wolframalpha.com/
This calculator is used for all kinds of data but you can enter food items into to it. I’m not sold on this being amongst the best calorie count sources but it is a neat tool to keep in your arsenal. To use it you would type a string of items into the search bar. For example: large apple + subway turkey sub. Then it will analyze what you typed in and it will give you the data your looking for.