Enter the mating date to get your dog's expected due date, the likely whelping window, and a week-by-week guide.
Dog pregnancy (gestation) lasts about 63 days from the date of mating — roughly 9 weeks. A healthy birth normally happens anywhere from 58 to 68 days, so 63 days is the average, not an exact deadline. This calculator adds 63 days to your mating date for the expected due date, and shows a likely whelping window of 61–65 days.
| Stage | What's happening |
|---|---|
| Weeks 1–3 (days 1–21) | Fertilization and implantation. No visible physical changes yet. |
| Week 4 (days 22–28) | Organs and spine develop. A vet can often confirm pregnancy by ultrasound around day 25. |
| Weeks 5–6 (days 29–42) | Puppies grow quickly. The mother's belly expands, appetite increases, and nipples swell. |
| Weeks 7–9 (days 43–63+) | Puppies develop skeletons — an X-ray around day 55 can count them. The mother's temperature drops below about 100°F roughly 24 hours before labor. |
Because sperm can survive several days inside the dog, a mating date only gives an estimate — a vet tracking ovulation gives the most accurate timeline. This is a general guide for information, not veterinary advice. Sources: standard canine gestation of ~63 days (58–68 day range) as used by veterinary and breeder references.