How do I estimate my dog's due date?

Count forward approximately 65 days from the date of the first mating. The normal whelping window is 58–72 days. For the most accurate estimate, enter the mating date into our calculator above — it shows a 14-day whelping window. For more precise dating, ask your veterinarian about ovulation timing, progesterone testing, or ultrasound.

How many puppies are in a litter?

Litter size varies widely by breed, age, and individual dog. Small breeds typically have 1–4 puppies, medium breeds 4–8, and large breeds 6–12, but these are rough averages only — individual litters can fall well outside these ranges. The most reliable way to count puppies is an X-ray around day 55–58 of pregnancy, once fetal skeletons are fully calcified and visible.

When should I prepare the whelping box?

Set up the whelping box by day 50 of pregnancy (about 1–2 weeks before the due date). Place it in a quiet, warm, draft-free area. Line it with newspapers topped with clean towels or whelping pads. Introduce your dog to the box early so she's comfortable. Start monitoring her temperature twice daily from day 56 — a sustained drop below 99°F usually indicates labor will begin within 24 hours.

Is this calculator a substitute for veterinary advice?

No. This calculator provides estimates based on the standard canine gestation window (58–72 days from first breeding, AKC/Merck Veterinary Manual). Every pregnancy is unique. Always consult a licensed veterinarian for pregnancy confirmation, health monitoring, whelping guidance, and emergency care. This tool is for planning purposes only.

Canine Pregnancy Calculator

Date of First Mating

Enter the date of the first mating. Breeding-date-based estimates are approximate (normal range: 58–72 days). For more accurate dating, consult your veterinarian for ovulation timing or ultrasound.

Enter a mating date to see your results

Select the date of the first mating to calculate the estimated whelping date, pregnancy progress, and key milestones.

What Is a Canine Pregnancy Calculator?

Estimate your dog's whelping window and track pregnancy milestones

A Canine Pregnancy Calculator estimates when your dog will whelp (give birth) based on her first mating date. When dated from breeding, canine gestation ranges from 58 to 72 days (AKC, Merck Veterinary Manual). We estimate 65 days as the midpoint with a ±7 day window.

Important

This calculator provides an estimate based on average canine gestation. Breeding-date-based estimates are inherently approximate — actual whelping dates can vary by several days. For the most accurate dating, consult your veterinarian for ovulation timing, progesterone testing, or ultrasound. Always involve a veterinarian in pregnancy management.

How Is the Whelping Date Estimated?

Based on the 58–72 day first-breeding window (AKC, Merck)

The estimated whelping date is calculated by adding 65 days (the midpoint of the 58–72 day first-breeding range per AKC and Merck Veterinary Manual) to the first mating date. A ±7 day window covers the full normal range.

Formula

Estimated Whelping Date = First Mating Date + 65 days

Sources: AKC (akc.org/expert-advice/health/how-long-are-dogs-pregnant): gestation from first breeding can range 58–72 days; Merck Veterinary Manual: ~63 days from ovulation, wider when dated from breeding.

Example

Dog first mated on May 15, 2026:

Earliest

Jul 12

Day 58

Estimated

Jul 19

Day 65

Latest

Jul 26

Day 72

Dog Pregnancy Week by Week

What happens during each phase of canine pregnancy

Early Pregnancy

Weeks 1–3 (Days 0–21)

Fertilized eggs travel to the uterus and implant around day 17–21. Your dog may show no visible signs yet. Continue normal feeding and exercise. Avoid nonessential vaccines or medications unless your veterinarian recommends them.

Mid Pregnancy

Weeks 4–6 (Days 22–42)

Fetal development accelerates. By day 28–30, an ultrasound can confirm pregnancy and detect heartbeats. You may notice increased appetite, weight gain, and enlarged nipples. Switch to high-quality puppy food by week 5.

Late Pregnancy

Weeks 7–9 (Days 43–65)

Puppies are fully formed by day 50 and visible on X-ray. The abdomen will be noticeably enlarged. Set up the whelping box by day 50. Start taking temperature daily from day 56 — a drop from ~101.5°F to ~98–99°F signals labor within 24 hours.

Common Mistakes to Avoid

Pitfalls that lead to incorrect whelping date estimates

Assuming a precise due date

Canine gestation varies by several days. The 58–72 day range from first breeding is normal. Use this calculator for planning, not as a clinical prediction.

Counting from the last mating instead of the first

Sperm can survive for several days in the reproductive tract, and ovulation timing relative to breeding significantly affects the actual whelping date. Always use the first mating date for the most consistent estimate.

Not preparing the whelping box early enough

Set up the whelping box by day 50. Introducing it late can cause stress and rejection. The dam needs time to acclimate to the space.

Waiting too long to confirm pregnancy

Ultrasound can confirm pregnancy as early as day 28–30. Early confirmation lets you adjust nutrition, supplements, and vet scheduling proactively.

Frequently Asked Questions

Common questions and detailed answers

Early signs (around week 3–4) include decreased appetite or morning sickness, slight weight gain, enlarged and darker nipples, clear vaginal discharge, and increased affection or nesting behavior. Around day 28–30, a veterinarian can confirm pregnancy via ultrasound or palpation. A relaxin hormone blood test can detect pregnancy from around day 25–30 after breeding; testing earlier may produce false negatives.

When gestation is dated from the first breeding (rather than from ovulation), the normal range is 58–72 days per AKC and Merck Veterinary Manual. We use 65 days — the midpoint of that range — as the best single-date estimate, with a ±7 day window covering the full normal span. Calculators that use 63 days are typically referencing ovulation-based dating, which is more precise but requires veterinary testing to determine.

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Last updated May 8, 2026