When we buy eggs in the market I choose the carton of Large eggs. Not the Jumbos, and not the Medium. Standing there, before all the options, I realize eggs come in sizes, but it's easy to forget. Over the years I have see carton after carton, one dozen eggs of like size and shape. Uniform, and consistent, and one comes to expect all eggs to be more or less about the same.
Our hens are starting to pick up the pace with their egg laying, and the varieties of color are fun and beautiful, and the size differences are interesting, too. If we're scrambling eggs, I can grab whatever is on hand. But when it comes to baking, I am having to take a little more consideration. A recipe might read, "Two large eggs," and some of our eggs are larger than others, but are they actually "Large eggs?" How do our large eggs compare with the sizing standards set by United States Department of Agriculture? So, when we want to follow a recipe carefully, and not confuse our small eggs from a truly "Small" egg, we have started weighing them. I've only done it a couple of times, and lucky I did, too, because our so-called large eggs, it turns out, are actually "Small," and our darling little small eggs, by the chart, are Peewee! Like I said, I've only bothered once or twice, because I am not usually concerned about the sizes... but somebody laid an egg that begs to be weighed and recorded!
See for yourself how our eggs measure up!
I found the handy chart, at Wikipedia, very helpful.