Dog Pregnancy Calculator
Dogs usually whelp 58–72 days after the first mating, 64–66 days after the LH surge, or 62–64 days after ovulation (Merck Veterinary Manual). Enter the date you know to get the due-date window.
Example: first mating on 1 November 2026 → whelping window 29 December 2026 to 12 January 2027, middle of the window 5 January 2027.
How it works
From the Merck Veterinary Manual, normal gestation in dogs is:
58–72 days from the first mating 64–66 days from the LH surge (or initial progesterone rise) 62–64 days from ovulation 56–58 days from the first day of diestrus
The mating date is the least precise, because sperm can survive in the female for days and mating rarely happens exactly at ovulation. Ovulation timing (progesterone or LH tests) gives a much narrower window. We show the middle of each window as a planning date. The AKC describes gestation as about 63 days from ovulation.
How to use it
- Choose what you know. First mating date, or the LH surge, ovulation or diestrus date from your vet’s tests.
- Enter the date. Add a second mating date if there was one.
- Plan with the timeline. Pregnancy checks, X-ray and the whelping window.
- Watch for labour. Take her temperature in the whelping window and know when to call the vet.
Dog pregnancy timeline
| When | What happens |
|---|---|
| About day 21 | Your vet may feel the puppies |
| Days 25–35 | Ultrasound can reliably confirm pregnancy and see heartbeats |
| Days 30–35 | Relaxin blood test can detect pregnancy |
| After about day 45 | Puppy skeletons show on X-ray |
| After about day 55 | X-ray is the best way to count the litter |
| Days 58–72 after first mating | Normal whelping window (62–64 after ovulation; 64–66 after the LH surge) |
| 8–24 hours before whelping | Rectal temperature drops to about 98.1–100 °F (36.7–37.8 °C) |
Days count from mating unless stated; when counted from mating they are approximate. Source: Merck Veterinary Manual.
Frequently asked questions
How long are dogs pregnant?
About 62–64 days from ovulation (63 on average per the AKC). Counted from the first mating, the normal range is wider: 58–72 days, because mating and conception do not happen on the same day.
How can I tell if my dog is pregnant?
Your vet may feel the puppies at about day 21, ultrasound can reliably confirm pregnancy from about day 25–35, and a relaxin blood test works from about day 30–35.
When can an X-ray count the puppies?
Puppy skeletons show on X-ray after about day 45, and X-rays after about day 55 are the best way to count the litter.
What are the signs that labour is near?
Her rectal temperature usually drops to about 98.1–100 °F (36.7–37.8 °C) 8–24 hours before whelping. She may also become restless, start nesting, stop eating or pant.
When should I call the vet during whelping?
Call if she strains hard for more than 30 minutes without a puppy, goes more than 2 hours between puppies, has more than 4 hours of active labour without a puppy, has not started 24–36 hours after the temperature drop, or has green-black discharge or heavy bleeding before a puppy.
When to see a vet
- Strong contractions for more than 30 minutes without a puppy.
- More than 2 hours between puppies (or more than 30 minutes with strong contractions).
- Active labour for more than 4 hours with no puppy.
- No whelping 24–36 hours after her temperature dropped.
- Green-black discharge or heavy bleeding before the first puppy.
- Whelping lasting more than 24 hours, or no puppies by day 72 after the first mating.
If you think your dog is in labour and something seems wrong, call your vet or an emergency vet now.
This is an estimate for general information, not veterinary advice. Every pet is different. Ask your veterinarian before changing your pet's diet, especially for puppies, kittens, pregnant or nursing pets, seniors, or pets with health conditions.
Sources
- Merck Veterinary Manual. Whelping and Queening in Bitches and Queens (gestation length, temperature drop). www.merckvetmanual.com/management-and-nutrition/management-of-reproduction-dogs-and-cats/whelping-and-queening-in-bitches-and-queens
- Merck Veterinary Manual. Dystocia in Small Animals (signs of prolonged or abnormal labour). www.merckvetmanual.com/reproductive-system/reproductive-diseases-of-the-female-small-animal/dystocia-in-small-animals
- Merck Veterinary Manual, Dog Owners. Management of Reproduction in Dogs (pregnancy tests and timing). www.merckvetmanual.com/dog-owners/reproductive-disorders-of-dogs/management-of-reproduction-in-dogs
- American Kennel Club. The dog reproductive cycle and how long dogs are pregnant (about 63 days from ovulation). www.akc.org/expert-advice/dog-breeding/dog-reproductive-cycle/
- Concannon PW. Reproductive cycles of the domestic bitch. Anim Reprod Sci. 2011;124(3–4):200–210. doi.org/10.1016/j.anireprosci.2010.08.028
- AAHA. 2021 AAHA Nutrition and Weight Management Guidelines for Dogs and Cats, Box 1: Energy requirement calculations (RER/MER life-stage factors). www.aaha.org/wp-content/uploads/globalassets/02-guidelines/2021-nutrition-and-weight-management/resourcepdfs/nutritiongl_box1.pdf
Full methodology: sources and methodology. Last reviewed 20 October 2026.