I have a simple question and I think I already know the answer but I wanted to be sure

I have a box of Orville Redenbacher spicy nacho popcorn and the calorie count isn't adding up. The box says that one serving is half the bag at 42g. I weighed it last night and the entire bag popped was only 65g. There were less than 10 unpopped kernels left in the bottom. I went by the weight but I wonder if that is right. In my experience, when I go by weight I usually end up getting less so I feel like I am cheating by getting more popcorn per serving than the bag says I should

. If the whole bag is only 60g, I can eat more than half for one serving. Am I right to go by weight?
On the same note, I am frustrated when the labels are misleading! I bought a bag of the new Kernels dill pickle popcorn at Walmart the other day. It said I could eat 5 cups for about 200 calories. I weight it out and I only ended up with about 2 cups for one serving

. I won't be getting that again, it is not worth the calories since I like quantity when I have the munchies