Welcome to the The Incredible Edible Egg™ Eggcyclopedia, where you can access the latest egg information from A-Z. The Eggcyclopedia was developed by the American Egg Board (AEB) on behalf of America's egg farmers who are committed to caring for their hens and producing high-quality eggs for you and your families.

Just click on any letter below to bring up a list of egg terms and their related definitions.


Look for shells that are clean and whole. Cracked eggs are always removed from production, but some may be broken in handling. Don’t use an egg if it’s cracked or leaking.

Proper handling and refrigeration are important factors in maintaining egg quality. Eggs lose quality very rapidly at room temperature, so buy eggs only from refrigerated cases, get them home quickly and refrigerate them immediately. At temperatures of 35 to 45ºF (3 to 7ºC), you can store eggs with insignificant quality loss for three to five weeks after you bring them home.

Eggs are marketed according to grade and size standards established by the U.S. Department of Agriculture (USDA) or by state departments of agriculture. The USDA shield on the egg carton means that the eggs have been graded by U.S. or state department of agriculture representatives for consistency with USDA’s standards for the voluntary grading of shell eggs.

Some egg packers may follow state standards, which must meet or exceed USDA standards. Some states have state seal programs which indicate that the eggs are produced within that state and are subject to continuing state quality checks. All eggs sold at the retail level must meet the standards for Grade B or higher.

Size and grade are two entirely different factors and bear no relationship to one another. Grade is determined by the interior and exterior quality of the egg at the time the egg is packed.

Size is determined by the average weight per dozen.

9 buying web


Egg grades are labeled AA, A and B. There is no difference in nutritive value between the different grades.

All eggs sold at the retail level must meet the standards for Grade B or better. Most eggs sold in supermarkets today are Grade AA or A. Because production methods are very efficient, eggs move so rapidly from laying house to market that you’ll find very little difference in quality between Grades AA and A. Although Grade B eggs are just as wholesome to eat, they rate lower in appearance when broken out. Few Grade B eggs find their way to the retail supermarket. Most go to institutional egg users such as bakeries or foodservice operations.

– See Breakout, Grading


Egg sizes are jumbo, extra large, large, medium, small and peewee. Medium, large and extra large are the sizes most commonly available because hens most often lay eggs of these sizes. Sizes are classified according to minimum net weight expressed in ounces per dozen.


Which Size to Buy

You can use any size egg for most basic egg recipes, including scrambled or fried eggs. However, most recipes for baked goods are formulas in which it’s important to maintain the proper proportion of liquid to dry ingredients and to have enough whole egg, white or yolk to perform the needed functions. Most baking recipes are based on large-sized eggs. (To substitute one size egg for another in recipes, see Size Equivalent.)

Most of the eggs sold in supermarkets are large-sized, but there are occasionally specials on other sizes. Use the following chart to find which size is the best buy.

To compare the price of large eggs to the price of medium eggs, for example, run your fingers down the columns to the figures closest to the prices per dozen for large and medium eggs. Then, go across to the price per pound for each size. The one selling for the lower price per pound is the better buy. Always compare the same grade of eggs for an accurate price comparison.


– See Grading, Size Equivalents

Inexpensive Egg Protein

Protein is an essential part of a nutritious diet but, for many people, foods that supply protein are some of the most expensive items on the grocery list.

Fortunately, the protein supplied by eggs is both high in quality and low in cost. It’s easy to compare the price of eggs to the price of other protein foods. A dozen large eggs weigh 1 1/2 pounds, so the price per pound of large eggs is two-thirds of the price per dozen. For example, if large eggs cost 90¢ per dozen, they cost 60¢ per pound. At $1.20 per dozen, large eggs are only 80¢ per pound.

Another helpful formula is that one egg equals one ounce of lean meat, poultry or fish. This means that you can use two eggs as your main dish at a meal or you can use eggs to “stretch” more expensive protein foods. For instance, you might use one chopped hard-boiled egg per serving along with half the usual amount per serving of expensive seafood in a casserole.

– See Meat Replacement, Protein