Dog Pregnancy Calculator

How long are dogs pregnant?

The short answer is about 63 days from ovulation, roughly nine weeks. The catch is that almost nobody knows the exact day of ovulation, so breeders count from something they can see: the breeding itself. That is why you will see two different numbers quoted, and both are correct.

• 63 days from ovulation, the physiological average.
• 64 to 66 days from a progesterone rise, which is measured with blood tests.
• 65 to 66 days from the LH surge, the hormone spike that precedes ovulation by about two days.
• 58 to 68 days from the first breeding, the widest and most common way owners count.

The reason the breeding-date window is ten days wide is sperm survival: healthy sperm can live inside the female for 3 to 7 days and fertilize an egg when it is released. Breed on day one of the fertile period and ovulation on day five, and you have effectively started the clock five days early. The AKC's guide to the canine reproductive cycle sets out the full timeline, and it is the source for the ranges used here.

Worked example: bred on May 1

Say your dog was bred on May 1, 2026 and you did not track ovulation.

• Estimated due date: July 3, 2026 (May 1 + 63 days).
• Earliest realistic: June 28 (day 58).
• Latest realistic: July 8 (day 68).

Now the milestones, all counted from the same May 1 start:

• Day 21. May 22. Ultrasound can usually confirm a pregnancy from here.
• Day 28. May 29. Fetal heartbeats are often visible; palpation may feel the sacs.
• Day 45. June 15. X-ray window opens and skeletons are mineralized enough to count puppies.
• Day 55. June 25. Whelping box in place and she should be comfortable with it.
• Day 58. June 28. Start twice-daily rectal temperatures to catch the pre-labor drop.

If you had confirmed ovulation instead and the breeding happened two days after it, the same litter would be expected three days earlier. June 30 rather than July 3. That is the whole reason the calculator lets you switch the method you are counting from.

Week by week: what is happening inside

Puppy development runs on a tight schedule. This table shows the standard milestones; dates in the right-hand column assume a May 1, 2026 breeding.

Two things surprise first-time breeders. First, the first three weeks are almost invisible, many dogs show nothing at all, and a dog that is a little off her food around day 20 is not necessarily sick. Second, the growth in the last two weeks is fast: a bitch can visibly gain weight and drop her belly in the final ten days. The VCA's overview of pregnancy in dogs covers the same stages from a clinical angle.

Signs labor is starting, and when to call the vet

Labor in dogs has three phases, and knowing them keeps you from panicking at the wrong moment.

• Stage one (6 to 12 hours). Restlessness, panting, nesting, refusing food, sometimes vomiting. She may want to be alone or glued to you. Uterine contractions are happening but not visible.
• Stage two. Visible straining and the arrival of puppies, typically 15 to 60 minutes apart. Each puppy comes in its own sac, which she usually breaks and eats.
• Stage three. The placenta passes after each puppy, and stages two and three then alternate.

The single most useful signal is temperature. From day 58, take her rectal temperature twice a day. Normal is about 100.5 to 102.5 °F; a drop below 99 °F generally means puppies within 12 to 24 hours. Take that reading to your vet as soon as you see it if you have any concerns about her progress.

Call a veterinarian immediately if: she strains hard for more than 30 minutes with no puppy, more than 2 to 3 hours pass between puppies, she has strong contractions for over an hour without progress, there is a green or foul discharge before the first puppy, or she seems weak, feverish or in pain. This calculator estimates dates only, it cannot detect a problem, and complications in whelping are emergencies.

Care changes worth making before the due date

Pregnancy care is mostly about small, early changes rather than a big event on day 63.

• Food. Stay on her normal adult diet for the first 4 to 5 weeks. From about week 5, transition gradually to a puppy or performance formula and increase the amount as her appetite allows, many vets suggest 25 to 50% more calories in the final third, split into three or four smaller meals.
• Exercise. Keep normal, gentle exercise going. Short familiar walks are better than nothing; avoid jumping, rough play, dog parks and anything with a fall risk in the last third.
• Parasite control. Many worms pass from mother to puppies, so deworming is usually scheduled with your vet rather than guessed at.
• Whelping box. Set it up by day 55 so she can get used to it. Line it with clean, washable bedding and put it somewhere quiet and warm, newborn puppies cannot regulate their own temperature.
• Supplies. Clean towels, a heating pad or heat lamp with a safe gap, a scale that reads in grams or ounces, and your vet's emergency number written down where you will see it.

None of this is a substitute for veterinary advice. A dog that is off her food for more than 24 hours, running a temperature, or showing any discharge should be seen by a vet regardless of what the calendar says.

Why the due date is an estimate, not an appointment

Every date this calculator produces is an estimate built from population averages. Real litters do not read the calendar: in practice, puppies arrive anywhere from day 58 to day 68, with day 60 to 65 covering the large majority. A litter born on day 59 is early but often fine; a litter still not delivered on day 70 deserves a veterinary check.

Three things narrow the estimate if you want a tighter one:

• Progesterone testing. Serial blood tests pin down the LH surge and ovulation within a day, which is the single biggest improvement you can make to accuracy.
• Ultrasound at day 21-25. Confirms the pregnancy exists and gives the vet a chance to check for problems.
• X-ray at day 45 or later. Counts skeletons, which matters enormously once you are whelping, you need to know when the last puppy is out.

Treat the output above as a planning window: when to set up the box, when to start temperature checks, when to clear your calendar. It is a reference estimate, not veterinary advice, and it cannot tell you whether your dog is pregnant or how many puppies are coming. Your veterinarian's examination is the only reliable answer to either question.