Here's what I found in one of my coops today. So the answer is...if the egg on the left weighing 104g....about 1 or 2....if the egg on the right, tipping the scales at 22g.....about 20.
Is the one on the right a bantam or just a fart egg? I would definitely crack them both into a little bowl before using them in my recipe - you may find several yolks in the one on the left and no yolk in the one on the right. LOL! What a contrast in egg size.
To take your question seriously about cooking with different-sized eggs, I'm the author of The Farmstead Egg Cookbook, so I know something about it A standard egg is 2 ounces, but I have hens that lay 3 ounce eggs, and a bantam White Leghorn who's eggs come in around 1 1/2 ounces. Usually omelets are made with 3 eggs. When you have a selection of bantam and large eggs, and have a recipe that calls for a lot of eggs (like 8, say) then it's best to weigh your eggs, or you could be quite off! So, I'd suggest getting a kitchen scale.The other thing to remember is that the proportion of yolk to white changes depending on the size of the egg. The smaller the egg, the larger the yolk. I once ruined a pound cake recipe using all bantam eggs - it was too yolky and the texture was off.
The tiny egg is a 'fart' or 'fairy' egg. I've just worked out that it probably is from a brown mutt pullet who is about the right age to start laying and was in that pen overnight.
It probably is best to weigh eggs for very specific recipes.