The first eggs that my girls laid as pullets were smaller than the eggs they now lay at 40 weeks. Most of the girls laid a 1.6 ounce egg for their first egg, and then over the next few days, the egg size rose to 1.8 ounces and even 2.0 ounces. Two of the girls still lay a 1.8 ounce egg. The other ten are now laying 2.0-2.2 ounce eggs for their first laying season. So far, I've only had one double yolk egg from the girls.
The first questions my family and friends asked when they were the recipients of a dozen eggs was "What size are the eggs?" Everyone was used to using the Large eggs purchased at the local grocery store. Hence, my internet search to find out what size egg the girls really laid. The size or weight class and minimum net weight per dozen comes from information I found in the United States Department of Agriculture Egg Grading Manual, Agriculture Handbook Number 75, Revised 2000.
Size or Weight Class
Jumbo=30 ounces per dozen
Extra Large=27 ounces per dozen
Large= 24 ounces per dozen
Medium=21 ounces per dozen
Small=18 ounces per dozen
Peewee=15 ounces per dozen
I calculated the average egg size by using the weight per dozen given in the manual. This is an "approximate" egg size and a guideline that I use for sizing my chicken's eggs.
Average Egg Size Per Weight Class
Jumbo=about 2.5 ounces
Extra Large=about 2.25 ounces
Large=about 2.0 ounces
Medium=about 1.75 ounces
Small=about 1.5 ounces
Peewee=about 1.25 ounces
