Hatch Rate Calculator

One number cannot tell you why a hatch went wrong. Seventy percent hatchability could mean a breeder flock with low fertility or a perfect flock ruined by a bad incubator, and the fix for each is completely different. This calculator computes all three professional metrics: hatchability, fertility rate, and hatch of fertiles, so you can see exactly where your losses happened.

How to use the calculator

Enter the total eggs you set and how many hatched for the headline hatchability figure. If you candled around day 10 and counted fertile eggs, enter that too and the tool adds fertility rate and hatch of fertiles, plus a diagnosis of where your losses came from. A fertile count is what separates "the flock has a problem" from "the incubator has a problem".

The formulas

Hatchability = (Hatched / Set) × 100, the figure every calculator shows. Two refinements used by hatchery professionals: Fertility rate = (Fertile / Set) × 100 measures the breeder flock, and Hatch of fertiles = (Hatched / Fertile) × 100 measures the incubator. If fertility is high but hatch of fertiles is low, your incubator (temperature, humidity, turning, egg storage) is the suspect; if fertility itself is low, look at the breeding birds.

Worked example

You set 77 eggs, candled 73 fertile, and 64 hatched. Hatchability = 64/77 × 100 = 83.12% (Good). Fertility = 73/77 × 100 = 94.81%. Hatch of fertiles = 64/73 × 100 = 87.67%. Diagnosis: both metrics are healthy, so the 13 lost eggs are normal background losses, not a systematic problem.

What other calculators miss

Every competing tool stops at hatched divided by set, which is the least informative of the three metrics: it mixes breeder-flock fertility with incubator performance into one number you cannot act on. The hatchery literature's key insight is that hatchability data is only interpretable when you know which calculation was used, yet none of the ranking calculators computes fertility or hatch of fertiles at all. This tool does all three and translates them into a plain-language diagnosis, and it rates your result against published benchmarks instead of leaving you to guess.

FAQs

What is a good hatch rate?
Above 75% is good, 55 to 75% is average, and below 55% is poor. Shipped eggs typically run 40 to 70% because handling damages them.

What is the difference between fertility and hatchability?
Fertility is the share of eggs that were fertile (from candling); hatchability is the share of set eggs that hatched. You can have 95% fertility and 60% hatchability if the incubator is at fault.

How do I count fertile eggs?
Candle around day 10 and count eggs showing veins and a growing embryo. Break out a sample of clears to check true fertility, since early-dead embryos can look infertile.

What temperature and humidity do chicken eggs need?
About 99.5°F (37.5°C) with 50 to 55% humidity for the first 18 days, raised to 65 to 75% for the final 3 days, turning eggs at least 3 times daily until lockdown.

Why did my shipped eggs hatch poorly?
Shipping shakes air cells and ages the eggs; 40 to 70% is normal for shipped eggs. Let them rest point-down for 12 to 24 hours before setting.

Can hatch rate exceed 100%?
Practically no. Double-yolked eggs can theoretically hatch twins, but the calculator flags hatched counts above the set count as an error.

How often should I calculate hatch rate?
After every incubation cycle. Tracking the three metrics over time shows whether a change in feed, breeders, or equipment actually helped.

Do the same metrics apply to quail or duck eggs?
Yes, the math is identical. Benchmarks differ by species and conditions: home quail incubation typically runs 60 to 85%.