Free breeder tool
Whelping date calculator
Enter the date you know and how you know it. The window narrows from two weeks to three days as the timing improves.
Date (YYYY-MM-DD or MM/DD/YYYY)
This date is the
Ovulation date
LH surge date
Breeding / tie date
Enter a date to see the whelping window and the milestone dates.
How the dates are calculated
Canine gestation is remarkably consistent when measured from ovulation: 63 days, give or take one. The LH surge precedes ovulation by about two days, so 65 days from the surge. A breeding date is unreliable because a tie can happen anywhere from a few days before to a few days after ovulation and sperm survive up to a week, which is why the breeding-date window is 57–72 days.
Ultrasound can confirm pregnancy from about day 25 after ovulation. Radiographs count puppies reliably from about day 55. Rectal temperature is taken twice daily from day 57; a drop below roughly 99°F (37.2°C) usually precedes labour by 12–24 hours.
How many days is a dog pregnant?
About 63 days from ovulation, or 65 from the LH surge. Counted from the breeding date the range is 57–72 days, because ovulation can happen days after the tie.
Which date should I use?
Ovulation from progesterone testing if you have it. Otherwise the LH surge. The breeding date gives a wide window and is a last resort.
When should I X-ray for a puppy count?
After about day 55 from ovulation, when fetal skeletons are mineralised enough to count.
BreedBloom does this automatically for every litter: due-date window, ultrasound and X-ray reminders, temperature checks, and per-puppy weight curves.
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