Pets · Dog breeding
Dog Due Date Calculator
One breeding date or two — enter the mating dates and get the most likely whelping date plus the full window in which healthy puppies can arrive.
- Most likely day 63
- Safe window 58–68
- Two-mating averaging
Dog Due Date Calculator
Please choose at least one valid mating date.
- Safe window opens (day 58)
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- Safe window closes (day 68)
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- Days until due date
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Why a due date is a range, not a day
Vets quote 63 days because it is the average from ovulation. But a bitch can ovulate a day or two after mating, and individual pregnancies vary, so healthy puppies can arrive any time from day 58 to day 68. The calculator shows the most likely date plus the full window — prepare the whelping area by day 56 so nothing is left to chance.
Mating date vs ovulation date
Most owners only know the mating date, which is what this calculator uses. Breeders who progesterone-test know the ovulation date and count 63 days from that for a tighter estimate. If you have two mating dates a day or two apart, entering both and averaging gives a slightly better result than guessing which one 'took'.
Preparing for the due date
By day 56: set up the whelping box somewhere warm, quiet and draught-free, and let the dog get used to it. Stock clean towels, a thermometer, dental floss or thread for cords, and your vet's emergency number. Start taking her temperature twice a day from day 58 — a drop below about 37.8°C (100°F) usually means labour within 12–24 hours.
Related guides and tools
Dog Due Date Calculator FAQs
Is the 63-day due date exact?
No — it is the average. Healthy puppies are born between days 58 and 68 from mating. Only your vet, with scans and temperature tracking, can narrow it further.
Why do vets prefer counting from ovulation?
Ovulation is the biological start of pregnancy, so it gives the most consistent 63-day figure. Mating-based dates include 1–2 days of uncertainty because mating can precede ovulation.
My dog mated twice — which date counts?
Enter both dates and use the average. Puppies from a single heat can have different fathers and slightly different conception days, so averaging the two matings is the most sensible estimate.
What if puppies come before day 58?
Puppies born before day 58 are premature and may not survive without intensive veterinary care. Call your vet immediately if labour starts this early.
How do I know labour is starting?
Common signs: temperature drop below 37.8°C, restlessness and nesting, loss of appetite, panting, and mild contractions. See our guide to the signs your dog is about to give birth.