How to use the dog pregnancy due date calculator
- Enter the mating date. If there were several matings, use the first date or ask your vet which to use.
- Leave the typical length at 63 days, or change it to the number your vet gives you. Open the advanced options to change the earliest and latest likely day.
- Read the estimated due date, the likely window and how far along the count is today.
- Use the week by week table to mark dates on a calendar. Print the page or copy the result to share it.
Formula
Due date = mating date + typical length (default 63 days)
Likely window = mating date + earliest day to mating date + latest day (defaults 58 and 72)
Week n = days 7 x (n - 1) to 7 x n - 1 after mating
The 63 day average (measured from ovulation) and the 58 to 72 day window (measured from mating) are commonly quoted figures and are editable. The tool only adds days to a date. It does not know anything about your dog's health.
Worked example
A mating on October 10, 2026 plus 63 days gives an estimated due date of Saturday, December 12, 2026.
The window runs from day 58, December 7, to day 72, December 21. On November 14 the count is at 35 days, which is 5 weeks, and the due date is 28 days away.
A mating on December 1, 2026 crosses the new year, with a due date of Tuesday, February 2, 2027.
Why the due date is a window
The length of a dog pregnancy varies by several days, and counting from a mating date is less exact than counting from ovulation, because sperm can survive for days and mating does not always happen on the day of ovulation. That is why the tool shows a window around the date and why the answer can change if your vet confirms timing with tests.
Planning ahead
Use the due date to plan the whelping area, the vet visits and time off. A vet can confirm a pregnancy and advise on timing. Ask your vet what signs mean you should call, because this tool has no medical information. To see how old a dog is in human years, try the pet age calculator, and to estimate a puppy's adult size later, the puppy weight calculator.
Counting days yourself
To check the arithmetic, you can use the date calculator to add 63 days to the mating date, or the days between dates tool to count from the mating date to today.
Assumptions and limits
- Pregnancy length is the number of days you enter. About 63 days is the usual figure measured from ovulation. Counted from the mating date, which can come days before ovulation, the range is roughly 58 to 72 days.
- The window is the earliest and latest day you enter and is not a medical range.
- Dates use the calendar with no time of day.
- This is a date estimate only and not veterinary advice. Talk to your vet about confirming the pregnancy and what to expect.
Frequently asked questions
How long is a dog pregnant?
About 63 days from ovulation is the usual figure. Counted from the mating date the range is wider, roughly 58 to 72 days, because mating can happen several days before ovulation. Your vet can give a better estimate with hormone tests or an ultrasound.
Why does my vet's date differ from this one?
A vet can use hormone tests or imaging to date the pregnancy more precisely than a mating date can. If you have a vet date, use it, or change the typical length here to match.
What if the dog mated more than once?
Using the first date gives the earliest estimate and the last date the latest. The window is a better guide than a single date, and your vet can help you decide.
Can I use this for other animals?
You can change the length in days for any species if you know it, but the labels and window defaults are for dogs, and the tool gives no guidance on any animal's health.