Accurate Frozen Dinner Calorie Method
I don't really do this most of the time because usually the calorie estimates on the box are close enough, but there is a way to calculate about how many calories are really in your frozen dinner.
There will still be some variation but you can get a more accurate count this way.
Each frozen dinner is labeled with a grams number right next to the serving size. For example, Smart Ones Chicken in Spicy Peanut Sauce is labeled this way: Serving Size: 1 package (255 g)
So here's what you do. Take a plate and put it on your food scale. Zero it out and make sure the unit is in grams. It should read Zero grams. Empty the cooked dinner onto the plate and see how many grams it is.
Let's say that you measure 270 grams of actual food in the frozen dinner. Take that number and divide it by the number of grams for the serving size.
270/255 = 1.059
Take this number and multiply it by the number of calories per serving. In this case, the calories for 1 serving at 255 grams are listed as 250 calories on the box.
So here's the math:
250 x 1.059 = 264.75
Now you have a more accurate calorie count.
If you've entered the frozen dinner information as a custom food in your list, then you would enter this as 1.06 servings in your food log.