Duck Egg Hatch Date Calculator

Key takeaways

• Most domestic duck eggs hatch on day 28. Muscovy takes 35 days; Metzer Farms puts the Indian Runner and the Crested slightly longer than 28 and hatchery Mallards slightly shorter.
• Candle first at day 7 — though two respected sources say day 10 instead, and the calculator shows you both.
• Stop turning at day 25 or day 26. The sources genuinely split on this and either is defensible.
• Published incubator humidity for duck eggs ranges from 45% to about 63%. A single exact number hides the disagreement.
• Weighing eggs is a better humidity check than any humidity reading: they should lose about 14% of their setting weight by day 25.

How long duck eggs actually take

Twenty-eight days covers almost every domestic duck you are likely to have. Cornell University’s Duck Research Laboratory, Penn State and Mississippi State Extension all give the same figure, and the hatcheries agree with them. What is worth knowing is how few breeds are ever broken out separately from that number.

Search for “Khaki Campbell incubation period” and you will find pages confidently giving you a breed-specific figure. None of the university or hatchery pages this calculator draws on gives one, or separates Khaki Campbell, Cayuga, Welsh Harlequin, Buff, Swedish, Aylesbury, Rouen or Magpie from the general duck figure. So the calculator gives them all the general 28-day figure.

Four kinds of duck genuinely are named separately:

• Muscovy — 35 days. Cornell, Penn State and Metzer Farms all say 35; Mississippi State gives 35 to 37. The reason for the gap is that Muscovy is not a mallard-derived duck at all. It is a separate species with a different natural history: it perches in trees, and Cornell’s Lab of Ornithology says it is usually silent rather than quacking.
• Indian Runner — 28.5 to 29 days. Slightly longer than the usual 28, like the Crested below. Metzer Farms says 28.5 on their hatching instructions page and 29 in their FAQ. Their own two pages disagree, so the calculator gives you the window.
• Crested — 29 days. Named by Metzer alone.
• Mallard — about 26.5 to 27 days for hatchery stock. Wild Mallards under a broody hen vary far more — Cornell’s Lab of Ornithology records 23 to 30 days in the field, because a natural nest is not a temperature-controlled box.

Call ducks are the interesting gap. None of the sources this calculator uses states a Call duck incubation period. Metzer sells them and puts everything it does not name separately at 28 days, so 28 is a reasonable inference from how their list is built — but it is an inference, not a published figure, and the calculator says so on the page rather than quietly presenting it as fact.

Candling: day 7, or day 10?

Both, depending on who you ask, and this is the first place the confident single answers on other sites start to come apart.

Cornell candles at about seven days and removes the infertile eggs. Metzer Farms agrees, and describes what you should see by then: a darker yolk, veins under the shell, and the beginnings of an embryo. Meyer Hatchery says day 10, and describes the embryo as a tiny spider with veins radiating from a dark spot. The British Waterfowl Association candles at day 10 and again at day 20.

The practical answer is that day 7 is early enough to spot a clear egg and late enough to be sure, and there is no penalty for looking again on day 10. What matters far more than the day is what you are looking for, and Metzer’s rule is the clearest statement of it anywhere: if you see clear, distinct veins it is probably alive, and if you do not see clear, distinct veins it is probably not.

Later in incubation the picture changes. By day 12 you can often see movement if you hold the egg still. By day 22 the embryo fills so much of the egg that there is little to see except around the air sac. By day 26 or 27 you can sometimes see the bill moving inside the air sac itself, which is the last good news you get before the pip.

The lockdown split, and why we show you both dates

Lockdown — stopping the turning and raising the humidity for the hatch — is where duck incubation advice quietly contradicts itself, and almost nobody says so.

Cornell keeps Pekin eggs in the setter for 25 days and transfers on day 25. Cackle Hatchery’s chart says turning stops at day 25. Mississippi State’s species table says not to turn duck eggs after the 25th day, which matches its rule of no turning in the last three days before hatching. Against that, Metzer Farms’ incubation table runs turning to day 25 and shows zero turns from day 26, and Meyer Hatchery says plainly to stop turning on day 26.

So: three sources point at 25, two at 26. Both are defensible, the difference is one day, and a duck egg that stops turning a day early or a day late is not in trouble. The calculator shows both dates because pretending otherwise would be the kind of false confidence that makes a first-time hatcher panic when their own reading disagrees with the tool.

Muscovy is thinner ground still. Cornell gives Muscovy’s 35-day length but no transfer day. Cackle Hatchery’s chart and Mississippi State’s species table both stop turning Muscovy eggs at day 31, and the calculator still flags it as thinly evidenced.

Temperature and humidity: what the numbers really look like

Temperature is the closest thing to agreement in duck incubation, and even here there is a split worth understanding. The duck sources cluster tightly: Cornell says 99.5°F, Kansas State says 99.25 to 99.5, Metzer says 99.5, the British Waterfowl Association says 37.4°C which is 99.3°F. Mississippi State’s species table gives 100°F for ducks in a forced-air incubator, half a degree above the rest, and says to add 2 to 3°F in a still-air one.

Humidity is a genuine mess, and the honest thing is to say so. Published figures for the main incubation period run from 45% at the bottom to about 63% at the top. Cornell and the British Waterfowl Association say 55%. Metzer says 57 to 58. Mississippi State’s duck row gives a wet bulb of 85 to 86°F at 100°F, which is about 54 to 57%; its 58 to 60% is a general figure for all eggs. Kansas State’s 86 to 88°F wet bulb works out at about 58 to 63%. Cackle’s chart allows down to 45%. The duck-specific sources cluster at 55 to 58, which is what this calculator shows. The incubator humidity converter turns any of these figures into the wet-bulb reading for your own incubator.

Lockdown humidity is wider again, from 55% to 81%, and the sources do not even agree on the shape of it. Cornell and Meyer describe two stages — raise it at transfer, raise it again once the first pip appears. Metzer sets a single figure of 81% across the whole hatching phase.

Which is why the most useful thing in this section is not a humidity number at all.

Weigh the eggs — it beats every humidity reading

Humidity is a means to an end. The end is that the egg loses the right amount of water over incubation, so the air cell grows to the right size and the duckling has somewhere to breathe before it pips. You can measure that directly.

Cornell gives the figure: common duck eggs should lose about 14% of their weight at setting by day 25. The British Waterfowl Association gives about 15% across incubation. Weigh a sample of eggs on the day you set them, weigh them again at each candling, and you will know whether your humidity is right in a way that a hygrometer sitting in a warm box cannot tell you.

Losing too much means humidity is too low; losing too little means it is too high. That single check does more for a hatch than agonising over whether 55% or 58% is correct.

From the first pip to a duckling

The waiting at the end is the hardest part, and it is where most avoidable damage gets done by well-meaning intervention.

Metzer Farms describes the sequence: after pipping, the duckling rests for 12 to 24 hours. That rest is normal and it is not a bird in trouble. When it starts again it works its way out in several bursts with breaks, and finishes about one to three hours later. Their threshold for stepping in is specific — a visible hole, the duckling in view, and no progress at all for 12 hours.

Two other timings are useful. Ducklings can be heard calling inside the egg up to 48 hours before they hatch, so the noise is a good sign rather than a distress signal. And a whole batch can take 72 hours from first hatch to last, so a still egg on the morning of day 28 is not a failed egg.

Once they are dry and on their feet, the next thing you need is a plan for the first weeks — and the brooder temperature in our housing and space calculator, because getting that wrong in week one undoes a good hatch.

What this calculator will not tell you

It will not tell you a still-air incubator temperature for duck eggs, because no duck-specific figure was found. Mississippi State’s 102°F is general poultry guidance, and passing it off as a duck number would be exactly the sort of quiet substitution this tool exists to avoid.

It will not give Muscovy-specific temperature or humidity, because no source publishes any — every chart found uses identical settings for Muscovy and everything else.

And it will not tell you whether your eggs are fertile. That is what candling is for, and it is why day 7 is on the timeline.

If you are earlier in the process than this — still working out whether your ducks are laying, or whether their eggs are worth setting — when ducks start laying and how duck eggs differ from chicken eggs are the two places to start.