Calculate This Farm · Guinea Hatching
Module · Farm

Guinea Fowl
Hatching

A 28-day incubation timeline for guinea fowl eggs. Most references say 26 or 27 days, but in practice keets often hatch on day 28. Plan for 28 and you won't be caught off guard.

See the math behind this calculator
Standard incubation
28 days

Sometimes hatches
Day 26 to 28

Lockdown begins
Day 25
Direction
Date
Fine-tune
Estimated hatch date -
Set date-
Days incubating-
Days elapsed-
Days remaining-
First candling-
Lockdown begins-
▸ Incubation milestone timeline
Day Milestone Date

The math

Guinea fowl incubation is one week longer than chicken incubation. Same protocol, just stretched: 28 days from set to hatch, lockdown on day 25, first candling around day 10.

hatch_date = set_date + 28 days
lockdown_date = hatch_date - 3 days

Frequently asked

Is it 26, 27, or 28 days?

You'll see all three numbers in different references. Under ideal incubator conditions a few keets can pip on day 26. The bulk of a clutch tends to hatch closer to day 28, so plan for 28 and treat earlier hatches as a bonus.

Why are guinea keets so much harder to hatch than chicks?

Two reasons. The shells are tougher, which means more reliance on humidity to soften the membrane before pip. And guineas are less domesticated than chickens, meaning less generations of selection for predictable incubator hatching. Hatch rates of 60 to 70% are normal even with good practice.

When should I first candle?

Day 10 is reliable. Guinea egg shells are darker and thicker than chicken eggs, which makes earlier candling harder to read. By day 10 a fertile egg shows clear veining and a visible embryo against the candler.

Can I put guinea and chicken eggs in the same incubator?

Yes if you're willing to handle the staggered hatch. Set guinea eggs first; add chicken eggs 7 days later. Both clutches hit lockdown roughly together. The complication is that you can't open the incubator during chicken lockdown when the guineas still have a few days to go - which means accepting reduced humidity for the guineas or skipping the parallel set.

Show the working

This is date arithmetic on a fixed incubation period. Everything is counted from the day the eggs go in. If any of it looks wrong, it might be - tell us what we got wrong.

Hatch date from set date hatch = set date + 28 days
Set date from a target hatch set date = hatch date − 28 days
Where you are now days elapsed = today − set date days remaining = hatch date − today
Lockdown lockdown = set date + 25 days
Candling checkpoints first candling = set date + 7 days second candling = set date + 25 days

Constants used

  • 28 days — incubation period for guinea fowl eggs, editable on the page
  • day 25 — lockdown — stop turning, raise humidity

Day one is the first full day of incubation, not the moment the eggs go in. Setting eggs in the evening and counting that as day one is the usual reason a hatch appears to run a day late.

The sources

Guinea fowl run to the same 28-day clock as turkeys. The one genuinely guinea-specific detail on this page, the late first candling, comes from the same source.

  1. Jacob J. Raising Guinea Fowl in Small and Backyard Flocks. University of Kentucky, via Poultry Extension. Puts guinea incubation at 26 to 28 days, notes it matches turkeys, and gives the day-10 candling point this page uses - guinea eggs are hard to read before then.
  2. Mississippi State University Extension Service. Incubation duration periods. The incubation lengths this page is built on - 21 days for chickens, 28 for turkeys - with the caveat that collection, storage and incubation conditions all move the actual date.

The day-10 candling point is a limitation rather than a preference. Guinea shells are hard to read before then, so an earlier check tells you little and chills the eggs for nothing.