Dog Pregnancy Due Date Calculator
Estimate a whelping date from the mating date, with the key gestation milestones dated along the way.
If there were several matings, use the first one for the earliest possible date.
Due date
Tue, 13 Oct 2026 63 days from mating
- Normal range
- Wed, 7 Oct 2026 to Thu, 22 Oct 2026
- Days elapsed
- 30
- Days remaining
- 33
- Weeks pregnant
- 4.3
| Day | Date | Milestone |
|---|---|---|
| 0 | Tue, 11 Aug 2026 | Mating Sperm can survive several days in the reproductive tract, so the true conception date may be later than this. |
| 18 | Sat, 29 Aug 2026 | Implantation Embryos attach to the uterine wall. Some bitches go off their food around now. |
| 25 | Sat, 5 Sept 2026 | Ultrasound confirmation Pregnancy can be confirmed by ultrasound from about day 25, and heartbeats seen. It does not give a reliable litter count. |
| 30 | Thu, 10 Sept 2026 | Relaxin blood test A blood test for relaxin is reliable from around day 30. |
| 40 | Sun, 20 Sept 2026 | Increase food Energy needs climb from here. Move gradually onto a puppy or gestation diet, fed in smaller, more frequent meals. |
| 45 | Fri, 25 Sept 2026 | X-ray for litter count Fetal skeletons mineralize and become visible on X-ray from about day 45. This is the reliable way to count puppies and to know when whelping is finished. |
| 55 | Mon, 5 Oct 2026 | Prepare the whelping box Set it up now so she can settle in. Start taking her temperature twice daily. |
| 61 | Sun, 11 Oct 2026 | Watch for the temperature drop Rectal temperature falling below about 37.2 degrees Celsius usually means whelping within 24 hours. |
| 63 | Tue, 13 Oct 2026 | Due date Average is 63 days from mating. Anything from 57 to 72 days can be normal. |
Gestation is measured from ovulation, not from mating, and sperm survive for several days. That is why the range from a mating date is as wide as 57 to 72 days. Progesterone testing at the time of mating narrows it to within a day or two.
How this is calculated
Canine gestation is remarkably consistent when measured from ovulation and quite variable when measured from mating. This calculator works from the mating date, which is what most owners have, and shows the resulting range honestly rather than presenting one date as certain.
due date = mating date + 63 days
normal range = mating date + 57 to 72 days Milestones
- Day 18. Embryos implant. Some bitches go off food around now.
- Day 25. Ultrasound can confirm pregnancy and show heartbeats.
- Day 30. Relaxin blood test is reliable.
- Day 40. Energy needs begin climbing; move onto a gestation diet.
- Day 45. Fetal skeletons mineralize and become visible on X-ray. This is the only reliable way to count puppies.
- Day 55. Set up the whelping box and start twice-daily temperature checks.
- Day 61. Watch for the temperature drop that precedes whelping by about a day.
- Day 63. Average due date.
Sources
- Merck Veterinary Manual. Breeding Management of Bitches (estrous cycle and gestation).
- Johnston SD, Root Kustritz MV, Olson PNS. Canine and Feline Theriogenology. Philadelphia: WB Saunders; 2001. Standard reference text for canine gestation length and whelping. No free full text.
Get the litter count
An X-ray from day 45 tells you how many puppies to expect, and that single piece of information changes how whelping is managed. Without it there is no way to know whether a bitch who has stopped pushing after four puppies is finished or has a fifth stuck. It is the most useful thing you can do before the birth.
Before the due date
Have your vet's out-of-hours number written down and know how long the journey takes. Know what normal looks like and what does not, because the decision to call is usually made at three in the morning by someone who has not slept. Dystocia is common in brachycephalic and toy breeds, and a planned caesarean is often safer than an emergency one.
This calculator produces dates. It is not a substitute for veterinary supervision of a pregnancy, and a first-time breeding in particular should be managed with a vet involved from confirmation onwards.
Common questions
How long are dogs pregnant?
About 63 days from mating, but anywhere from 57 to 72 days can be normal. Measured from ovulation rather than mating, gestation is far more consistent at 63 days give or take a day.
Why is the due date range so wide?
Because sperm survive in the reproductive tract for up to a week, so a mating can happen days before ovulation. The pregnancy clock starts at ovulation, not at mating, which is why a mating date alone gives a two-week window.
When can pregnancy be confirmed?
Ultrasound works from about day 25 and shows heartbeats, but it is unreliable for counting puppies. A relaxin blood test is accurate from around day 30. X-ray from day 45 gives an accurate count, which matters during whelping so you know when she is finished.
How do I know whelping is about to start?
Rectal temperature drops below about 37.2 degrees Celsius roughly 24 hours beforehand, so take it twice daily from day 55. Other signs are restlessness, nesting, refusing food and panting.
When should I call the vet during whelping?
Strong contractions for 30 minutes with no puppy; more than two hours between puppies when more are expected; a puppy visible but stuck for more than ten minutes; green or black discharge before the first puppy; or a bitch who is exhausted, collapsed or in obvious distress. Have the emergency number to hand before the due date.
How much should a pregnant dog eat?
Roughly normal for the first five weeks, then rising sharply. By the final week she may need 30 to 60% more than maintenance, and during peak lactation two to four times maintenance. Move to a puppy or gestation diet from around day 40, fed in smaller and more frequent meals as space in the abdomen runs out.