There are LOTS of online programs and programs you can download for free where you can log your food. Most of them will calculate for you, how many calories, or fat or carbs you’ve had. I am doing the medifast diet, so I use their free online tool, mymedifast.com. But there are a ton of programs. I find it useful because most of them have all the food in them, with all the nutritional info, including fast food and restaurant menus. I find that cheating is not what does me in, but underestimating how much I am actually eating. Here is how I do it. I log in each morning and I put in what I am going to eat for the day. Then either that night, or the next morning, I make any adjustments (add something that I hadn’t accounted for, or take off something I didn’t eat. Then each week I log my weight. When I first started doing it, I was SHOCKED at how many more calories I was actually eathing than I thought.
In addition to mymedifast, I also really like www.calorieking.com