Dog pregnancy calculator
Pick the date you know and what it marks, and get an estimated due date with the likely whelping window. The more precisely the date is known, the narrower the window. Hormone testing gives the best estimate.
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- Today
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- Days since the date
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- Days to the estimate
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How long is a dog pregnant?
Dog pregnancy lasts about nine weeks, around 63 days from ovulation. Counting from the mating date is less precise, because sperm can survive for days and fertilization does not always happen on the day of mating. That is why the window from a mating date is wide.
| Date you know | Typical days | Window |
|---|---|---|
| Mating date (single mating) | 63 | 56 to 68 |
| Ovulation date | 63 | 62 to 64 |
| LH surge (from a hormone test) | 65 | 64 to 66 |
| First day of diestrus (from vaginal cytology) | 57 | 56 to 58 |
Veterinary reproduction sources report that whelping comes 64 to 66 days after the LH surge, which is 62 to 64 days after ovulation, and that after a single mating it can come as early as 56 days or as late as 68 days. Counting from the first or the last of several matings can change the estimate by up to about two weeks. The 63 day figure from a mating date is the common rule of thumb.
What to do with the date
Your vet can confirm the pregnancy and estimate litter size with ultrasound or X-ray, and can tell you when to expect whelping. Ask the vet for a plan for the last two weeks, including what to do if labor does not start. If your dog goes past the end of the window, or seems unwell at any time, call your vet. For feeding during pregnancy, see how much to feed a dog and ask your vet how to adjust it.
Questions
How many days are dogs pregnant?
About 63 days from ovulation, or roughly nine weeks. From a single mating the whelping date can fall anywhere from about 56 to 68 days later.
Why is the window from a mating date so wide?
Fertilization does not always happen on the day of mating, and ovulation timing varies between dogs. Hormone tests (progesterone or LH) pin down ovulation, which makes the estimate much more precise.
Can this tell me if my dog is pregnant?
No. It only estimates dates if she is pregnant. Ask your vet to confirm the pregnancy.
What if I do not know the exact date?
Use the first mating date and read the whole window, not only the middle. Your vet can often refine the date with ultrasound.
Does this work for cats?
No, this calculator is for dogs only.
Sources
- International Veterinary Information Service (IVIS), Recent Advances in Small Animal Reproduction, "Canine pregnancy: predicting parturition and dystocia" (gestation length from the LH surge, ovulation and a single mating).
- UC Davis School of Veterinary Medicine, health topics on canine pregnancy (56 to 58 days from the first day of diestrus, 64 to 66 days from the LH surge).
Last reviewed 2026-10-26. This page is general information and not veterinary advice.