How do I calculate my dog's due date?

Enter the first mating date into our calculator. If there were multiple matings, add additional dates — the calculator averages them for a more accurate estimate. Key milestones: ultrasound at day 28, X-ray at day 45, whelping box prep at day 55.

What are the stages of dog pregnancy week by week?

Dog pregnancy progresses through distinct stages: Weeks 1-2 — fertilization and embryo travel to the uterus, no visible signs. Week 3 — embryos implant; some dogs experience morning sickness. Week 4 — ultrasound can confirm pregnancy (day 25-28); nipples begin to enlarge. Week 5 — weight gain becomes noticeable; fetal heartbeats detectable by stethoscope. Week 6 — abdomen visibly enlarges; increased appetite. Week 7 — hair loss on belly (nesting area preparation); you can feel puppies move. Week 8 — milk production may begin; puppies are fully developed. Week 9 (day 58-68) — delivery. Set up a whelping box by day 55 in a quiet, warm area.

When can you confirm a dog pregnancy?

Pregnancy can be confirmed by a veterinarian through several methods at different stages: abdominal palpation (day 21-28, requires experienced hands), ultrasound (day 25-28, can detect heartbeats and estimate litter size), relaxin hormone blood test (day 25-30, highly accurate), and X-ray (day 45+, can count skeletons and confirm litter size most accurately). Home pregnancy tests for dogs are unreliable. Our gestation calculator helps you schedule these confirmations by marking the key dates on your timeline.

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Dog Gestation Calculator

Calculate your dog's due date, track key developmental milestones, and prepare for whelping.

交配发生在什么时候？

首次交配日期

Key Knowledge

How Long Are Dogs Pregnant?

Dogs are pregnant for 63 days (9 weeks) from ovulation, with a normal range of 58–68 days. Sperm can survive in the female reproductive tract for up to 7 days, so the mating date and conception date may differ slightly — which is why our calculator accepts multiple mating dates.

Source: AAHA Canine Reproduction Guidelines

Canine Gestation Timeline

Day 0-4: Fertilization. Day 22-28: Ultrasound confirms pregnancy. Day 45-50: X-ray shows fetal skeletons. Day 55-58: Prepare whelping box. Day 63: Expected delivery. Day 28-32: Fetal heartbeats visible on ultrasound. Use a quiet, warm area (24-26°C) for the whelping box. Have a heat lamp ready for puppies (29-32°C the first week).

Source: AVMA Canine Reproduction Resources

Ultrasound vs. X-ray — When?

Ultrasound is earliest (day 22-28) and detects heartbeats; X-ray from day 45 counts litter size via visible skeletons. The two methods serve different purposes. Ultrasound cannot reliably count litter size. X-ray lets the vet count skulls/spines for an accurate litter count — most useful from day 45 onward.

Source: AAHA Canine Reproduction Guidelines

Preparing a Whelping Box

Set up by day 55 in a quiet, draft-free room at 24-26°C (75-80°F) — large enough for the mother to stretch but with low sides for easy entry. Use washable bedding: newspaper topped with towels or vet bedding. Have a heat lamp ready for puppies (kept at 29-32°C the first week).

Source: AVMA Canine Reproduction Resources

Data verified by petsMetrics using peer-reviewed veterinary sources. Citations: ASPCA, AVMA, AAFP. Last reviewed: 2026.

The Science Behind the Dog Gestation Calculator

Canine gestation averages 63 days from ovulation (±5 days), based on decades of veterinary reproductive science compiled by AAHA and AVMA. Our calculator uses the mating date(s) as input, adds a 2-day fertilization window (accounting for sperm viability), and projects three due dates: earliest (mating + 58 days), most likely (mating + 63 days), and latest (mating + 68 days). Key milestones — ultrasound at day 28, X-ray at day 45, whelping box at day 55 — are benchmarked against AAHA Canine Reproduction Guidelines.

References: AAHA Canine Reproduction Guidelines; AVMA Canine Reproduction Resources— via petsMetrics

Plan Your Dog's Vaccination Schedule

Puppies on the way? Make sure you know the vaccine timeline. Use our vaccination schedule to generate a personalized immunization plan based on age and region.

See Vaccine Schedule →