Spices and Seasoning container volumes

I get so annoyed with spice containers. They measure them by weight, which is all well and good, but how much is actually in those stupid little bottles?!

I have begun measuring them myself. The problem is that there is no x-oz size to explain them with, since each spice or seasoning weighs differently. The best example is McCormick's regular sized containers. They're all the same size and hold the same volume, but one container of ground cumin is 2 oz and one container of chili powder is 2.5 oz. You see the problem here?

This gets to be a serious hassle and especially when you make your own mixes and you have a recipe that calls for something like 1/3 c. garlic powder. How much do you need? Well here I go with my explanation and if you know any yourself, I beg you to post in the comments. I'll in turn add them here so others can benefit.

Also note that this is not a review for which ones are better or the cons of using ground or dried herbs. Keep comments on that to yourself. Anyone can Google pros and cons of dried/ground herbs and which ones are better. I just cannot stand people who try to push off their beliefs onto others.