How to calculate cost per egg
The same flock produces eggs at $3.95 or $4.93 a dozen depending on one decision about the coop.
The short answer
Cost per egg is your total annual cost divided by the eggs you actually collect, not the eggs the breed is advertised to produce. The two biggest choices are whether you include the coop and whether you use a realistic laying rate, and together they can move the answer by a third.
The formula
annual eggs = birds x realistic eggs per bird per year
cost per egg = annual cost / annual eggs
cost per dozen = cost per egg x 12
Realistic means measured, not published. Breed figures are peak-season output from birds in their first laying year under commercial conditions, and a backyard flock does not live there.
Worked example
Six hens, $414.66 of running cost, $102.75 of coop depreciation, laying 210 eggs each rather than the 240 the breed claims:
annual eggs = 6 x 210 = 1,260
running cost only: 414.66 / 1,260 = 0.329 → 3.95 a dozen
with coop: 517.41 / 1,260 = 0.411 → 4.93 a dozen
at the advertised 240 each: 517.41 / 1,440 = 0.359 → 4.31
Same birds, same feed. $3.95 or $4.93 a dozen depending on whether the coop counts, and $4.31 if you believe the breed leaflet. All three get quoted as the cost of keeping chickens.
Why real laying rates are lower than published ones
Moult. Most hens stop laying entirely for six to twelve weeks a year while they regrow feathers, and a bird that is not laying is still eating.
Daylight. Output drops sharply through winter without supplementary lighting, and a lot of keepers choose not to light the coop for the birds' sake, which is a defensible decision with a measurable cost.
Age. Laying falls off after the second year. A flock kept for five years without replacement produces far fewer eggs in years four and five while costing the same to feed.
The comparison that makes the number mean something
Compare against the eggs you would actually have bought. Against the cheapest cage eggs almost no backyard flock wins, and against premium organic free-range most do comfortably.
Picking the flattering comparison is the standard move in every article on this subject. If you would never buy the cheapest eggs, comparing against them understates your saving; if you would, comparing against organic is telling yourself a story.
What to do with a surplus
Selling eggs at the gate changes the arithmetic quickly, because the marginal cost of the extra eggs is only feed while the price is retail. A dozen sold at $5 against a marginal feed cost of about $2 covers ground fast.
Rules vary and matter. Many jurisdictions allow small-scale gate sales with light or no registration and become strict above a threshold, so it is worth checking before it becomes a habit rather than after.
What this leaves out
- Assumes eggs are collected and used. Waste and breakage are real and rarely counted.
- Excludes the value of manure, pest control and the birds themselves at the end of laying, all of which offset cost to some degree.
- Uses layer pellet pricing. Mixed feeding, kitchen scraps and forage all change the feed line and are hard to price honestly.
Common questions
- How many eggs will a hen lay in a year?
- A good hybrid layer in its first year can approach 280 under ideal conditions. Across a mixed-age backyard flock, 180 to 220 is a more honest planning figure and using the higher number is the most common way cost per egg gets understated.
- Should the coop count in the cost per egg?
- For deciding whether to start, yes, because you have to buy it. For deciding whether to keep going once you already own one, no, because that money is spent either way. The two questions are different and deserve different numbers.
- Why are my eggs costing more than shop eggs?
- Usually flock size against fixed costs, or a laying rate lower than you assumed. Six hens carrying a coop built for twelve is expensive per egg, and so is a flock where two birds have stopped laying and nobody noticed.
Spreadsheets that do this
The formulas above, already built and checked — so you fill in your numbers rather than the arithmetic.
Related guides
Last reviewed 22 August 2026