Yes, your chickens’ eggs will get bigger. Hens start laying small eggs and gradually increase in size over their first several months of production. Most backyard hens are producing large to extra-large eggs by about 40 weeks of age, and the eggs continue to grow slightly after that before plateauing.
How Eggs Change in the First Year
When a young hen (called a pullet) starts laying around 18 to 22 weeks old, her first eggs are noticeably small. These “pullet eggs” are completely normal. Over the following weeks and months, each egg tends to be slightly heavier than the last as her reproductive system matures and her body grows.
The rate of increase varies by breed and individual bird, but the pattern is consistent: a rapid jump in egg size during the first few months of laying, then a gradual climb that levels off. Research on laying hens shows that egg weight follows a curve, rising steeply at first and then approaching an upper limit unique to each hen. Some birds top out around 56 grams per egg, while others reach 66 grams or more. By 40 weeks of age, most modern breeds are laying eggs that fall into the large, extra-large, or even jumbo category.
USDA Egg Sizes for Reference
It helps to know what “large” and “extra-large” actually mean. The USDA classifies eggs by the total weight of a dozen:
- Medium: 21 ounces per dozen (about 50 grams each)
- Large: 24 ounces per dozen (about 57 grams each)
- Extra-large: 27 ounces per dozen (about 64 grams each)
- Jumbo: 30 ounces per dozen (about 71 grams each)
A kitchen scale is the easiest way to track your flock’s progress. If your pullets are producing 45-gram eggs right now, you can expect those numbers to climb steadily over the coming months.
Breed Plays a Major Role
Your hen’s genetic ceiling for egg size is largely set by her breed. Larger-bodied breeds tend to lay bigger eggs, though it’s not a perfect rule. Orpingtons (8 to 10 pounds), Plymouth Rocks (7.5 to 9.5 pounds), and Jersey Giants (10 to 13 pounds) are known for producing consistently large brown eggs. Rhode Island Reds and Australorps, both in the 6.5 to 8.5 pound range, are reliable large-egg layers as well.
Smaller breeds like Leghorns (4.5 to 6 pounds) still produce impressively sized white eggs relative to their body weight, which is why they dominate commercial egg production. Bantam breeds and ornamental chickens, on the other hand, will always lay smaller eggs regardless of age or diet. If you’re raising a mixed flock, expect noticeable differences in egg size between breeds even when the hens are the same age.
Diet Directly Affects Egg Size
What you feed your hens is one of the few factors you can control. Protein is the single biggest dietary lever for egg size. Research comparing hens on high, medium, and low protein diets found a striking difference: hens on the highest protein rations produced eggs averaging about 59 grams, while those on the lowest protein diet averaged only about 53 grams. That’s the difference between a solidly large egg and a medium one.
A standard layer feed with 16% to 17% protein supports good egg size for most hens. If your eggs seem smaller than expected, check that your flock isn’t filling up on scratch grains, kitchen scraps, or free-range foraging at the expense of their balanced feed. Treats should make up no more than about 10% of total intake.
Fat matters too, specifically a type called linoleic acid. This fatty acid is essential for building the lipoproteins that form egg yolk. Hens fed diets rich in linoleic acid (found in sunflower seeds, safflower oil, and soybean oil) consistently produce larger eggs than hens on low-fat diets, because more linoleic acid supports larger yolks. You don’t need to supplement oil directly, but choosing a quality layer feed that includes soybean meal or similar ingredients ensures adequate levels.
Heat Shrinks Eggs
If your eggs seem to get smaller during summer, you’re not imagining it. Heat stress causes hens to eat less, and reduced feed intake means fewer nutrients available for egg production. Studies in hot, humid climates have documented reductions of about 3.4% in egg weight during prolonged heat exposure. That might sound small, but it can bump an egg down a full size category.
Hens also divert energy toward cooling their bodies (panting, seeking shade) instead of egg production, so you may see both fewer and smaller eggs on the hottest days. Providing shade, ventilation, cool water, and feeding during the cooler parts of the day all help minimize the effect.
Double Yolks and Other Surprises
Young hens whose reproductive systems are still syncing up sometimes release two yolks at once, producing an oversized double-yolk egg. These are harmless curiosities, not a sign of what future eggs will look like. Older hens that naturally produce extra-large eggs can also lay the occasional double-yolker. The frequency typically drops as a young hen’s laying cycle becomes more regular over the first few months.
When Bigger Isn’t Better
While most chicken keepers are happy to see egg size increase, there is a point where very large eggs create problems. Double-yolk eggs and jumbo singles require more effort to pass, and hens that regularly strain can develop a condition called prolapse, where internal tissue is pushed outward through the vent. Overweight hens are especially susceptible because of weakened muscles and a tendency to produce larger eggs.
If you notice a hen consistently producing enormous eggs and showing signs of straining, bloody vent tissue, or lethargy, it’s worth adjusting her diet. Reducing protein to 15% after 36 weeks of age can slow the rate of egg size increase, which is actually a strategy some flock owners use deliberately. Keeping hens at a healthy body weight through proper feeding (not too many high-calorie treats) also reduces the risk.
The Timeline to Expect
Here’s a rough progression for a typical backyard hen. At 18 to 22 weeks, she starts laying small to medium eggs. By 30 weeks, most hens are producing medium to large eggs. Around 40 weeks, she’s likely hitting large or extra-large. After about a year of laying, egg size plateaus near her genetic maximum, though it may creep up very slightly in her second year. In subsequent years, hens tend to lay fewer eggs overall, but the individual eggs are often slightly larger than in year one.
So if you’re staring at a carton of small pullet eggs and wondering whether this is as good as it gets, just give it time. The combination of maturity, good nutrition, and moderate temperatures will do most of the work for you.