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 (68 days) to represent the normal range of canine gestation. The 63-day average is the widely cited figure from veterinary reproduction sources, measured from the estimated day of fertilization — which is usually close to, but not always exactly, the mating date, since sperm can remain viable inside the female for several days.
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.