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Dog Pregnancy Calculator

Use this free dog pregnancy calculator to estimate when your dog's puppies will arrive. Enter the mating date or the ovulation date, pick your dog's breed size, and the calculator will give you the estimated due date plus a week-by-week timeline of vet checks, nesting, and whelping preparation. It is a handy planner for first-time breeders and for owners who want to be ready well before labor starts.

How it works

A dog's pregnancy lasts about 63 days, or 9 weeks, counted from ovulation. The calculator simply adds 63 days to the date you enter. If you enter a mating date of January 1, the due date is March 5: January has 31 days, so January 1 plus 30 days reaches January 31, plus 28 days of February reaches February 28, and 5 more days reach March 5. The same rule works from an ovulation date, and the ovulation date is the more accurate starting point, because sperm can survive for several days before ovulation, so mating can happen a few days before the pregnancy truly begins.

The normal range from mating is about 58 to 68 days, which is why the calculator also shows a whelping window of about four days either side of the due date. A dog that whelps at day 60 or day 66 from mating is usually still within the normal range. If labor has not started by day 68 to 70 from mating, or if the dog shows signs of distress, call a vet right away, because an overdue pregnancy can become dangerous for both the mother and the puppies.

Breed size does not change the due date, but it does change what to expect. Small breeds usually have 1 to 4 puppies, medium breeds usually have 5 to 8, and large breeds usually have 6 to 12. First litters are often smaller than later ones. The litter-size guidance in this calculator is a rough range only; an ultrasound from about day 28 or an X-ray from about day 45 gives a far better count, and an X-ray late in pregnancy also shows whether any puppy is too large for a natural birth.

The timeline breaks the 9 weeks into practical stages. Weeks 1 and 2 are quiet: the embryos travel to the uterus and implant, and the dog looks and acts normal. Weeks 3 and 4 are when a vet can first confirm the pregnancy with an ultrasound, usually from day 25. In week 5 the belly starts to show and the appetite rises, so food should increase gradually rather than all at once. Weeks 6 and 7 bring nesting behavior, digging, and restlessness, which is the signal to set up the whelping box in a warm, quiet spot. Weeks 8 and 9 are whelping preparation: milk comes in, the belly drops, and the dog's temperature usually falls below 100 degrees Fahrenheit about 12 to 24 hours before labor.

Feeding and care change across the pregnancy too. For the first five weeks, the dog's normal diet is usually fine. From week 5 onward, most vets suggest increasing food by about 10 percent per week, reaching roughly 30 to 50 percent more by the end, and switching to a high-quality puppy food for the extra calories. Gentle walks should continue, but strenuous exercise, jumping, and rough play should stop. Never give medicines or supplements during pregnancy without a vet's approval.

Worked example

A small-breed dog mated on January 1, 2026.

Step 1: Start from the mating date — January 1, 2026.
Step 2: Add 63 days — January 1 plus 31 days reaches February 1, plus 28 days reaches March 1, plus 4 more days reaches March 5.
Step 3: The estimated due date is March 5, 2026.
Step 4: The whelping window is about 4 days either side — March 1 to March 9, 2026.
Step 5: Read the litter guidance — a small breed typically has 1 to 4 puppies.
Step 6: Read the timeline — a vet ultrasound can confirm pregnancy around January 26 (day 25), nesting should start around February 5 (week 6), and whelping preparation runs from February 19 (week 8) to the due date.

The owner should book the vet check for late January, set up the whelping box in early February, and be ready for labor from March 1 onward. If no puppies have arrived by March 9, the vet should be called.

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