Hens and eggs
Egg production tracker and lay rate calculator
Counting eggs every day is the easiest way to spot a problem in your flock early. Use the calculator below to work out your lay rate, how much feed a dozen eggs takes and what a dozen costs you.
Work out your lay rate, feed and cost per dozen
- Lay rate
- 80%
- Feed per dozen eggs
- 1.71 kg
- Cost per dozen eggs
- 1.29
How to calculate lay rate
Lay rate (also called hen-day production) is the share of your hens that laid on an average day:
- Lay rate = eggs collected ÷ (number of hens × number of days) × 100.
- Example: 10 hens laying 56 eggs in a week is 56 ÷ (10 × 7) × 100 = 80%.
Hen-housed production divides the eggs by the number of hens you started with instead, so it also reflects birds you lost. For a small flock, the hen-day lay rate is the more useful week-to-week number.
Feed per dozen and cost per dozen
- Feed per dozen eggs = feed used (kg) ÷ (eggs ÷ 12).
- Cost per dozen = (feed cost + other costs, such as bedding) ÷ (eggs ÷ 12).
Tracking these month by month shows whether a change of feed, an older flock or the time of year is costing you money.
Why egg numbers drop
Common reasons are shorter days in autumn and winter, the annual moult, age, stress, broodiness, worms or mites, and changes to feed or water. A daily log lets you see when the drop started and what changed at the same time, which is the first thing a vet will ask.
Keeping the log in Herdtrail
Each flock gets a daily log of eggs collected, cracked or damaged eggs, feed, water, deaths and birds added or removed. Herdtrail works out the bird count, the 7-day lay rate, feed per dozen and mortality for you, and egg sales go into your farm money. A whole flock counts as one animal, so most backyard keepers stay on the free plan.