Updated · Published by Radif Partners
Dog pregnancy calculator: when is my dog due?
A due date with an honest window, from the mating date or, much more precisely, from your vet's progesterone timing.
Siena & Milani, Animals (2021), review of whelping-date prediction · checked
Counted from the day of mating, a dog's pregnancy can last anywhere from 57 to 72 days, so a single due date 63 days later is only the middle of a two-week window. The reason is that sperm survive for days in the female's tract and the eggs need time to mature after ovulation, so the mating date says little about when fertilization happened. Veterinary studies reviewed in 2021 in the journal Animals show that timing from the hormone surge that triggers ovulation is far tighter: whelping falls about 65 days after the LH surge, and progesterone measured before breeding predicted the date within a day or two in most bitches. This calculator handles both. Enter the date you have, say what it is, and you get the expected whelping date, the normal window around it and the date by which the whelping area should be ready. Litter size and breed shift the length by a day or two, which is why a vet's ultrasound or X-ray in late pregnancy remains the way to fine-tune the plan.
Runs in your browser: nothing you type is sent or stored. Dates are estimates; your vet's scans and tests take precedence. How the figures are built.
Mating date, LH surge or ovulation: which to use
If all you know is when the dogs mated, choose the mating date: the calculator counts 63 days and shows the 57 to 72 day window. If your vet ran progesterone tests and gave you the day of the LH surge, choose that: whelping is expected about 65 days later, give or take a day or two. If you were given the estimated day of ovulation, the count is about 63 days.
Breeders who plan a caesarean, or whose bitch has had trouble whelping before, use the progesterone-timed dates for exactly this reason: a two-week window is too wide to schedule surgery safely.
What changes the length of a pregnancy
The 2021 review found that age, parity and the type of mating do not change the length counted from ovulation, but litter size does. Bitches carrying one or two puppies averaged about 65 days, those with three to nine about 63, and very large litters a little less. Breed also plays a part: in the studies cited, Labrador Retrievers whelped earlier than Golden Retrievers or hounds.
A small litter running a few days long is therefore common. A bitch going well past the window, or showing contractions without producing a puppy, needs a vet the same day.
Confirming the pregnancy
There is no reliable home pregnancy test for dogs. Your vet can confirm pregnancy by ultrasound a few weeks after breeding, by a blood test for the hormone relaxin, or by X-ray late in pregnancy, once the puppies' skeletons show, which is also the best way to count them before whelping.
Knowing the number matters on the day: if contractions stop while puppies remain, you will know to call. Ask your vet which test suits the stage your dog has reached.
Getting ready in the last weeks
Prepare a whelping box in a quiet, warm room at least a week before the expected date and let the bitch sleep in it. Many owners take her temperature twice a day in the final week, because a drop often comes in the day before labor; ask your vet what reading to watch for.
Keep your vet's number and the nearest emergency clinic's on hand. Feeding usually changes in late pregnancy and lactation, when energy needs climb steeply: plan the diet with your vet rather than with a maintenance calculator.
Count of days to whelping, by starting point
| Starting date | Expected whelping | Normal range |
|---|---|---|
| Date of mating | day 63 | days 57–72 |
| LH surge (progesterone test) | day 65 | days 64–66 |
| Ovulation (progesterone test) | day 63 | days 61–65 |
From Siena and Milani (2021) and the studies it reviews; the ovulation range covers the breed averages reported there.
Not a substitute for a veterinarian
Pregnancy and whelping can go wrong quickly. Green or bloody discharge without a puppy, strong contractions for more than half an hour without a birth, or a bitch past her window all call for a vet at once.
Sources
- Siena & Milani, Animals (2021), parameters for predicting the whelping date in dogs (read October 11, 2026)
- Merck Veterinary Manual, reproduction and pregnancy in dogs, owner edition (read October 11, 2026)
- American Kennel Club, breeding and whelping guidance for owners (read October 11, 2026)