Canine pregnancy runs on a fairly predictable clock: about 63 days from mating to whelping. This calculator uses that standard gestation length to estimate your dog's due date, show a countdown, and lay out what to expect week by week — so you can plan ahead for whelping day.
How the Dog Pregnancy Due Date Calculator works
The calculator adds 63 days to the mating date you enter to produce a headline due date, and also shows an early estimate (58 days) and late estimate (72 days). Veterinary references note that the mating date can be a poor proxy for ovulation and conception because sperm may remain viable for several days, so use the dates as a planning window and confirm concerns with a veterinarian.
Inputs and what they mean
The only input is the mating (breeding) date — the day your dog was bred. If your dog was bred more than once over a multi-day breeding window, using the first day gives you the earliest possible due date, and using the last day gives you the latest; many owners simply use the date of the most likely fertile mating. A veterinarian can narrow this down further with progesterone testing or ultrasound.
Limits and edge cases
This calculator is a planning tool, not a diagnostic one. It cannot confirm that a dog is actually pregnant, predict litter size, or detect complications. Because ovulation timing varies between individual dogs, treat the result as a window rather than a guaranteed date, and rely on a veterinarian for pregnancy confirmation (typically by ultrasound around day 28) and for any concerns as the due date approaches.