Dog due date calculator and whelping calendar

How long are dogs pregnant?

About 63 days, or nine weeks, is the figure most people hear. The honest answer is a window, and how wide it is depends on which date you count from. The calculator uses the ranges in the Merck Veterinary Manual and the pregnancy timeline published by reproduction researcher Patrick Concannon:

So a dog first mated on Mar 1, 2026 could whelp anywhere from Apr 28 to May 12, with May 3 (day 63) as a sensible date to plan around. Have everything ready by the start of the window, not the middle.

Why the mating date gives a wider window

A dog's heat behavior is a poor guide to when she actually ovulates. She may accept a male several days before or after, and once she ovulates her eggs need another 2 to 3 days to mature before they can be fertilized. Sperm, meanwhile, can survive inside her for a week or more. A mating on day one of standing heat and a mating a week later can produce puppies on the same day, which is why Merck gives a 15-day range from breeding.

Progesterone blood tests during heat remove most of that guesswork. Your vet can pinpoint the LH surge (the hormone signal that triggers ovulation), and whelping follows it 64 to 66 days later in almost every dog. A vaginal smear showing the first day of diestrus works too: count 56 to 58 days. If you are planning a cesarean, this precision matters, and it is worth asking your vet about before the next heat. Our heat cycle calculator helps you see when that heat is due.

Whelping calendar: what to do when

Day numbers count from the mating, or from ovulation when your vet has timed it. Each step is approximate by a few days. For what is happening to the puppies in each of those weeks, see our dog pregnancy week by week guide.

The ultrasound confirms she is pregnant and the puppies are alive. The late X-ray is the one that tells you how many to expect, so you know whether she has finished or a puppy is stuck. For food, keep her on her usual amount for the first six weeks, then increase gradually to about 1.5 times her normal intake in the last three weeks, ideally with a food labelled for gestation and lactation.

How do I know labor is close?

The most reliable home sign is her temperature. In most dogs the rectal temperature drops to about 98 to 100°F (36.7 to 37.8°C) 8 to 24 hours before whelping, as her progesterone falls. Taking it morning and evening in the last week shows you her usual reading, so the drop stands out.

First-stage labor follows: she gets restless, scratches and digs at her bedding to make a nest, and looks for a quiet corner. Many dogs stop eating in the last day. This stage normally lasts 12 to 24 hours. In the second stage she strains visibly and the puppies arrive, usually 30 to 60 minutes apart. Each comes in a sac that the mother tears open and licks away.

When to call the vet during whelping

Most dogs whelp without help. Call your vet or an emergency clinic straight away if you see any of these:

• Strong straining for 30 minutes without a puppy.
• More than 2 hours between puppies when you know more are inside.
• Weak, occasional straining for 4 hours without a puppy.
• No labor within 24 to 36 hours after her temperature drops.
• First-stage restlessness for more than 24 hours without straining.
• Dark green, black or bloody discharge before the first puppy, or a foul smell.
• Fresh bleeding that lasts more than 10 minutes.
• A puppy or fluid-filled bubble visibly stuck in the birth canal.
• Her temperature rises above 103°F (39.5°C).
• Whelping still going on after 24 hours in total.

After the birth, a bloody or foul-smelling discharge 24 to 48 hours later also needs a vet. Save the numbers in your phone before the window opens, and find out which clinic near you is open at night.

What if my dog goes past her due date?

With a mating date, more than 70 days counts as a prolonged pregnancy, even though the outer edge of the normal range is 72. With a hormone-timed date there is much less slack: nearly every dog whelps by day 66 after the LH surge. Past those points, or if her temperature dropped more than a day ago and nothing has happened, call your vet rather than waiting. An ultrasound shows whether the puppies' heartbeats are still normal, and your vet can decide whether to induce labor or operate.