Calories in Chicken Breast Oven Roasted

Is this accurate calories ? http://www.livestrong.com/article/43609-nutritional-information-cooked-chicken-breast/
I have been using this to log my chicken 3oz/85g turns out to be 142 calories. To me it seems like the calories are too low because when I measure my cooked chicken based on how many calories I want to eat it seems like TOO much chicken to eat.
I do not want to measure it raw because it is messy and I make a lot of chicken at once and I don't know how I would know which breast is how many calories.
How do you calculate your chicken calories?