Dog Whelping Calculator

How to Use This Calculator

Enter the date of mating or artificial insemination. Because all dog breeds share essentially the same 63-day gestation length, the breed dropdown is provided mainly for reference. Click Calculate Due Date to see the predicted whelping date, the earliest and latest dates within the normal range, and a full milestone timeline you can use to plan vet visits and whelping preparation.

For the most accurate prediction, ask your vet about progesterone testing at the time of breeding — it pinpoints ovulation directly, which removes most of the natural uncertainty in a mating-date-only estimate.

Whelping Box Setup

Introduce the whelping box by around day 50–53 so your dog has time to settle in before labor begins. The box should be:

• Large enough for the dam to stretch out fully in any direction
• Lined with whelping pads or clean towels — not loose bedding, which can suffocate newborn puppies
• Fitted with a low pig rail around the inside perimeter to stop the dam from accidentally crushing a puppy against the wall
• Placed in a quiet, warm, low-traffic area of the house
• Kept at 85–90°F (29–32°C) for the newborn puppies, using a heat lamp positioned over one side only so puppies (and the dam) can move away from the heat if needed

Signs of Imminent Whelping

• Temperature drop below 99°F (37.2°C): the single most reliable predictor — whelping typically begins within 12–24 hours. Start checking rectal temperature twice daily from around day 56–58.
• Nesting behavior: rearranging bedding, digging at the whelping box, seeking out secluded spots.
• Loss of appetite: many dogs skip their last meal or two before labor begins.
• Restlessness and panting: increased pacing, shivering, and visible discomfort.
• Increasing vaginal discharge: clear mucus increasing in volume as labor approaches.

What to Prepare

Beyond the whelping box itself, have a plan in place before labor starts:

• Confirm your regular vet's hours and have an emergency/after-hours vet number ready — most whelpings happen at night
• Know roughly how many puppies to expect (an X-ray after day 45 gives an accurate count)
• Set up a quiet space away from household traffic and other pets
• Have a plan for weighing and logging each puppy as it's born
• Clear your schedule around the predicted date — whelping can start with little warning once the temperature drop occurs

Whelping Supply List

When to Call the Vet

• Strong contractions continue for more than 30 minutes without a puppy being delivered
• More than 2–4 hours pass between puppies while the dam still appears to be in labor
• The dam seems exhausted and stops contracting before all expected puppies have arrived
• Greenish discharge appears before the first puppy is born
• A puppy appears visibly stuck in the birth canal
• The dam has been in Stage 1 labor (restless, nesting, no visible contractions) for more than 24 hours without progressing

Frequently Asked Questions

Sources & References

• American Kennel Club — Canine breeding and whelping guidelines
• Merck Veterinary Manual — Canine parturition
• Cornell University College of Veterinary Medicine — Canine whelping

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