Dog Pregnancy Calculator
Find your dog’s likely due date and whelping window, plus the key dates to plan for.
Estimated due date
Nov 6, 2026
Possible window: Sun, Nov 1, 2026 to Sun, Nov 15, 2026 (58–72 days from breeding).
- Sep 25, 2026Day 21: Blood test for relaxin becomes possible from about day 21–25 (ask your vet)
- Sep 29, 2026Day 25: Ultrasound can usually confirm pregnancy from about day 25–30
- Oct 9, 2026Day 35: Appetite and belly size start to increase; talk to your vet about feeding
- Oct 19, 2026Day 45: X-ray can count puppies from about day 45 onward
- Oct 30, 2026Day 56: Set up the whelping box; start taking her rectal temperature twice a day
Call your vet if she has strong contractions for 20–30 minutes with no puppy, or goes more than 2 hours between puppies.
Quick answer
Dogs are pregnant for about 63 days. From a breeding date, count 63 days for the likely due date, but expect puppies anywhere from day 58 to day 72. If your vet timed ovulation, the estimate is tighter: 63 days from ovulation, or 64–66 days from the LH surge.
How do I use the dog pregnancy calculator?
- Choose which date you know. Most owners only know the breeding date; breeders using progesterone tests may know ovulation or the LH surge.
- Enter the date. If she was bred more than once, add the last breeding date too.
- Read the estimated due date and the full window. Plan to be home for the whole window.
- Use the milestone dates to book an ultrasound (from about day 25) and an X-ray (from about day 45).
What formula does the dog pregnancy calculator use?
From ovulation: due ≈ date + 63 days (window 61–65)
From LH surge: due ≈ date + 65 days (window 64–66)
Two or more breedings: window = first + 58 to last + 72 days
The breeding range (58–72 days) and LH range (64–66 days) are from the Merck Veterinary Manual. The ovulation figure (63 days, give or take 1–2) is from Cornell’s Riney Canine Health Center. The wide breeding window exists because sperm can survive for about a week in the female, and eggs need a couple of days to mature after ovulation, so conception can happen days after mating.
How is the calculation done?
Using an example breeding date:
- Start from the breeding date: Mon, Mar 2, 2026.
- Add 63 days for the most likely due date: Mon, May 4, 2026.
- Add 58 days for the earliest normal date (Wed, Apr 29, 2026) and 72 days for the latest (Wed, May 13, 2026).
- If she was bred again two days later (Wed, Mar 4, 2026), the most likely dates become May 4, 2026 to May 6, 2026 and the window stretches to Fri, May 15, 2026.
- Milestones count from the same date: ultrasound from about day 25 (Mar 27, 2026), X-ray from about day 45 (Apr 16, 2026), whelping box ready by day 56 (Apr 27, 2026).
Worked example: ovulation timed by progesterone tests
Your vet’s progesterone tests show ovulation on Wed, Mar 4, 2026. Add 63 days: the estimated due date is Wed, May 6, 2026, with a window of May 4, 2026 to May 8, 2026. That five-day window is much easier to plan around than the two weeks you get from a breeding date, which is why vets time ovulation for planned C-sections.
Dog pregnancy timeline, week by week
| Week | What to expect |
|---|---|
| Week 1–2 (days 1–14) | Fertilization and early embryo development. No outward signs. |
| Week 3 (days 15–21) | Embryos implant in the uterus around days 17–21. Some dogs have mild morning sickness. |
| Week 4 (days 22–28) | A vet can often feel the swellings or see them on ultrasound from about day 25. Relaxin blood tests turn positive around now. |
| Week 5 (days 29–35) | Weight gain starts. Puppies develop quickly; talk to your vet about when to switch to a growth or all-life-stages food. |
| Week 6 (days 36–42) | Belly and nipples enlarge. Appetite increases. |
| Week 7 (days 43–49) | Puppy skeletons show on X-ray from about day 45, so your vet can count them. |
| Week 8 (days 50–56) | Movement may be visible. Set up the whelping box somewhere quiet and warm. |
| Week 9 (days 57–65) | Take her rectal temperature twice a day. A drop below about 99°F usually means labor within 24 hours. |
For more detail on each stage, read dog pregnancy week by week.
What should I prepare before whelping?
- A whelping box with low sides, in a quiet, warm room, ready about a week before the window opens.
- Clean towels, a digital thermometer, a scale for weighing puppies, and a notebook for times and weights.
- Your vet’s number and the nearest 24-hour emergency clinic, written down.
- A plan for money: emergency C-sections can be expensive, especially for flat-faced breeds.
When should you see your vet?
Book a check-up once you suspect pregnancy. During labor, call your vet or an emergency clinic right away if:
- Strong contractions last 20–30 minutes with no puppy.
- She strains for 8–10 minutes with a puppy or fluid-filled sac stuck in the birth canal.
- More than 2 hours pass between puppies and you know more are inside.
- You see green discharge not followed quickly by a puppy, or bloody discharge before the first puppy.
- Her temperature is over 103°F, or 24 hours pass after a temperature drop with no labor.
Frequently asked questions
How long are dogs pregnant?
About 63 days from ovulation. Counted from breeding, it can be anywhere from about 58 to 72 days, because sperm can survive several days and breeding dates don’t always match ovulation.
How can I confirm my dog is pregnant?
A vet can usually confirm pregnancy by ultrasound from about day 25 to 30, or with a relaxin blood test from about day 21–25. An X-ray after about day 45 can count puppies.
What if she was bred on more than one day?
Enter the first and last dates. The calculator widens the due window to cover both: from 58 days after the first breeding to 72 days after the last.
When should I call the vet during whelping?
Call your vet if she has strong contractions for 20–30 minutes without a puppy, strains for 8–10 minutes with a puppy stuck, goes more than 2 hours between puppies, has green or bloody discharge before the first puppy, or runs a temperature over 103°F.
Does breed change the due date?
Only a little. Gestation length is similar across breeds, though some studies find small differences between breeds and litter sizes. The date you count from matters far more than the breed.
Why is the due date more exact from ovulation?
Because conception follows ovulation closely. Vets time ovulation with progesterone blood tests. From ovulation, whelping is 63 days give or take a day or two; from the LH surge, 64–66 days. From a breeding date alone, the window is two weeks wide.
Sources
- Merck Veterinary Manual. Whelping and Queening in Bitches and Queens (gestation 58–72 days from breeding; 64–66 days from LH surge). merckvetmanual.com
- Cornell University Riney Canine Health Center. The normal whelping process (63 days from ovulation; up to 2 hours between puppies). vet.cornell.edu
- VCA Animal Hospitals. Breeding for Dog Owners: Problems at Birth (warning signs during labor). vcahospitals.com
- Kustritz MVR. Pregnancy diagnosis and abnormalities of pregnancy in the dog. Theriogenology 2005;64(3):755–765. doi.org
Vet disclaimer: These are estimates for healthy pets. Your vet knows your pet. Ask them before changing diet or care, especially for puppies, kittens, seniors, pregnant pets or pets with health conditions. Read our medical disclaimer.