Dog Pregnancy Calculator

Enter the date your dog was bred to estimate her whelping (due) date. Canine gestation averages about 63 days, with a normal range of 58 to 68 days.

Quick Facts

Method
Due date = breeding date + 63 days
Normal whelping window is 58-68 days from a single mating; 63 ± 1 day from ovulation.

Your Results

Estimated
Estimated due date
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~63 days after the chosen date
Earliest expected
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Start of normal window
Latest expected
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End of normal window
Whelp-watch begins
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Day 58 — start monitoring

Ready

Enter the breeding date and calculate the due date.

How the dog pregnancy due date is calculated

Dogs (Canis familiaris) have a remarkably consistent gestation length. Counted from the day of ovulation, puppies are born after about 63 days — biologically closer to 63 ± 1 day. This calculator applies that constant to the date you enter:

Estimated due date = breeding date + 63 days.

The catch is that the day you observe a mating is not necessarily the day the eggs are fertilized. A female dog remains fertile for several days, and canine eggs must mature for about two days after ovulation before they can be fertilized, then survive for a few more days. Sperm can live in the reproductive tract for up to a week. As a result, whelping can occur anywhere from 58 to 68 days after a single observed mating even though the true biological gestation is close to 63 days. That is why the calendar range from a mating date is wider than the tight 63-day average.

Three reference points for the same pregnancy

  • From the breeding (mating) date: average 63 days, normal range 58-68 days.
  • From confirmed ovulation: 63 ± 1 day. Ovulation is timed by a veterinarian using serum progesterone (ovulation occurs at roughly 5 ng/mL) or vaginal cytology.
  • From the LH surge: 65 ± 1 day. The luteinizing-hormone surge triggers ovulation about two days later, so counting from the LH surge adds two days to the ovulation figure.

Why owners and breeders need the date

Knowing the due date lets you set up a quiet whelping box a week ahead, arrange time off, keep emergency veterinary contacts handy, and recognize when labor is overdue. It also anchors the pregnancy timeline: fetal heartbeats can be detected by ultrasound from about day 25, skeletons become visible on X-ray from about day 45, and an accurate puppy count is usually only reliable on radiographs taken after day 55.

A pre-whelping temperature clue

In the last week, a bitch's rectal temperature normally sits around 100-102.5 °F (37.8-39.2 °C). Roughly 12-24 hours before labor it typically drops below 99 °F (about 37.2 °C) as progesterone falls. Taking her temperature twice a day near the due date is a practical, no-cost way to anticipate whelping.

Frequently Asked Questions

How long are dogs pregnant?
About 63 days on average, measured from ovulation, with a normal range of roughly 58 to 68 days when counted from a single observed mating. Gestation length is similar across breeds; a Chihuahua and a Great Dane both carry for about nine weeks, though very large litters sometimes deliver a day or two early.
Why is the range from the breeding date so wide?
Because the mating date and the fertilization date can differ by several days. A bitch can be receptive for about a week, sperm survive for days, and canine eggs need roughly two days to mature after ovulation before fertilization. The true gestation stays near 63 days, but which calendar day that lands on depends on when ovulation actually happened relative to the mating you saw.
Can a vet predict the exact whelping day?
Much more precisely, yes. By timing ovulation with progesterone testing (or the LH surge), a veterinarian can predict whelping to within about a day: 63 days from ovulation or 65 days from the LH surge. This is especially valuable for planning a possible cesarean in brachycephalic breeds such as Bulldogs.
When should I worry that she is overdue?
If more than 68-70 days have passed since the last mating, or more than 65 days since confirmed ovulation, with no signs of labor, contact your veterinarian. Also seek help if her temperature has dropped and dropped-then-risen without puppies, if she strains for more than 30-60 minutes without producing a puppy, or if there is dark-green discharge before the first puppy — these can signal a problem.

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