Hatch rate calculator
Three numbers from one hatch tell you whether the problem was the flock or the incubator. Enter what you set, what candled fertile and what hatched.
Fertility
83%
4 infertile of 24 set
Hatch of fertile
80%
4 fertile eggs lost
Hatch of set
67%
Chicks ÷ every egg set
A solid hatch. Minnesota's bulletin notes even commercial hatcheries may not beat 80 percent of eggs set.
When a hatch goes wrong
The University of Minnesota's hatching bulletin pairs each symptom with its usual causes. Mississippi State publishes a longer troubleshooting chart with corrective measures.
| What you see | Likely causes |
|---|---|
| Eggs candle clear, no blood ring or embryo | No rooster in the flock; Poor flock management; Eggs stored below 40°F, or too old before setting |
| Eggs candle clear but show blood or a tiny embryo when opened | Incubator temperature too high; Eggs stored below 40°F or above 80°F before setting |
| Embryos dead before hatching time | Eggs not turned at least 3 times a day; Lack of ventilation; Incubator temperature set too high or too low; Breeder flock with poor hatchability or an inadequate ration |
| Pipped but not hatched; chicks dead in the shell; sticky chicks; shells stuck to chicks | Low average humidity; Low average temperature; Low humidity at hatching time; A short spell of excessive heat |
| Hatching early, with bloody navels | Temperature too high |
| Not pipping until day 21 or later | Temperature too low |
| Some chicks early, then a slow, dragging finish | Temperature too high |
| Crippled chicks | Abnormalities in development; Poor nutrition of the hens; Incubator temperature too high |
Planning the next batch? The incubation calculator gives the dates and the sourced settings for 16 species, and the humidity converter turns the tables' wet-bulb readings into the percent your incubator shows.
Common questions
- What is a good hatch rate?
- Minnesota's extension bulletin warns that even commercial hatcheries with specialised equipment may not hatch more than 80 percent of the eggs they set, and that chickens and some upland game birds are much easier than waterfowl, with goose eggs particularly difficult. For ratites, Oregon State's bulletin says a grower who hatches at least half of all eggs set is probably doing well. Judge a small tabletop incubator against those numbers, not against 100.
- What is the difference between fertility, hatch of fertile and hatch of set?
- Fertility is the share of eggs set that were fertile, found at candling: it measures the breeding flock. Hatch of fertile is the share of fertile eggs that hatched: it measures the incubation. Hatch of set (hatchability) is chicks divided by every egg set, and mixes the two. Keep them apart and the number that is low tells you where to look.
- My fertility was fine but half the embryos quit. What happened?
- That pattern points at the incubator or the egg storage, not the flock. Minnesota's table lists eggs not turned at least three times a day, poor ventilation, and a temperature set too high or too low for embryos that die before hatch; low humidity, low temperature, or a short overheating for chicks that pip and die. Check your thermometer against a second one before the next batch.
- Hatching and Brooding Small Numbers of Chicks (AG-FO-0631). Melvin L. Hamre, Minnesota Extension Service, University of Minnesota. Reviewed 1990.
- Trouble Shooting Failures with Egg Incubation. Mississippi State University Extension.
- Raising Ratites: Ostriches, Emu, and Rheas (PNW 494). James C. Hermes, Pacific Northwest Extension (Oregon State University). July 1996.
We read each document ourselves and last checked this page against them on October 5, 2026. Where they disagree, we show you the disagreement instead of picking a winner quietly.
Keep every hatch on record
Log eggs set, fertile and hatched for each run in PoultryPal and it keeps your fertility and hatch-rate trends, so the second batch learns from the first. Hatching records are free. Free to download on iOS and Android.
