Hello ChicksHow to calculate hen-day egg production
Short answer: Hen-day egg production (%) = eggs collected in a day ÷ number of live hens that day × 100. Use the hens alive on that day, not the number you started with.
The formula
Hen-day production tells you what share of your hens laid an egg on a given day. Divide the eggs collected by the hens alive that day and multiply by 100.
Example: a shed has 5,000 hens alive and you collect 4,250 eggs. 4,250 ÷ 5,000 × 100 = 85%.
Use birds alive today, not birds housed
Hen-housed production divides by the birds you originally placed. It is a different number. As birds die or are culled, hen-housed production falls even when the remaining hens lay well. For day-to-day decisions, use hen-day.
Update the bird count every day you record deaths or culls, or the percentage will drift.
Mistakes that distort the number
Counting broken or floor eggs inconsistently makes the percentage jump. Decide once whether you count all eggs laid or only saleable eggs, and keep that rule. Both are useful; do not mix them.
Treating a day you did not record as zero eggs makes the average look worse than it was. Keep "no record" separate from "zero".
Comparing farms with different flock ages is unfair. A young flock near peak lays a higher share than an old flock. Compare a flock with its own recent weeks.
How Hello Chicks helps
Hello Chicks keeps the live bird count from your recorded deaths and culls, shows hen-day rate for each flock, and tells you when a day was not recorded instead of counting it as zero.