Veterinary Disclaimer: This tool is for informational purposes only. Always consult a licensed veterinarian for pregnancy confirmation, health monitoring, and whelping assistance.
If breeding occurred on multiple days, use the first mating date.
Due Date
June 6, 2026
Day 63
Earliest
June 1, 2026
Day 58
Latest
June 13, 2026
Day 70
49 days (7 weeks) until estimated due date
Pregnancy Milestone Timeline
7
Fertilization complete
April 11, 2026
Embryos travel to uterus for implantation.
16
Implantation
April 20, 2026
Embryos attach to uterine wall. Embryonic development begins in earnest.
22
Heartbeats detectable
April 26, 2026
Early fetal heartbeats can be detected via ultrasound.
25
Ultrasound confirmation
April 29, 2026
Vet ultrasound can confirm pregnancy and give a litter size estimate.
35
Rapid fetal growth
May 9, 2026
Puppies grow quickly. Dam may show early belly changes.
45
X-ray window opens
May 19, 2026
Skeletons calcified enough to count puppies accurately via X-ray.
55
Introduce whelping box
May 29, 2026
Set up the whelping box and begin twice-daily temperature monitoring.
58
Earliest normal whelping
June 1, 2026
Some dams deliver from day 58. Monitor closely from this point.
63
Due date (average)
June 6, 2026
Average whelping day. Normal full range is day 58 to 70.
70
Latest normal date
June 13, 2026
Contact your vet immediately if no labor has started by this point.
How Canine Gestation Is Calculated
Dog gestation is counted from the date of ovulation, which typically coincides with or occurs within a few days of mating.
Due date = Mating date + 63 days Earliest = Mating date + 58 days Latest = Mating date + 70 days
Normal whelping window: day 58 to day 70
The 63-day average comes from measuring gestation from ovulation. Because sperm can survive in the reproductive tract for several days, actual conception may occur up to 5 days after mating, which is why the normal range spans 12 days.
Who Uses This Calculator?
Dog breeders
Track breeding dates across multiple litters and prepare for whelping on time.
First-time pet owners
Unexpected or planned first pregnancy with no prior experience managing a whelping timeline.
Veterinary clinic staff
Quick due date estimate during a consultation without pulling up charts.
Rescue organizations
Pregnant strays often arrive with unknown breeding dates. Use physical exam stage to estimate mating date and back-calculate.
How to Use the Calculator
1
Enter the mating date
Select the date of the first breeding. If your dog was bred on multiple consecutive days, use the first date.
2
Read the due date
The orange card shows the average due date (day 63) plus the earliest (day 58) and latest (day 70) normal dates.
3
Follow the milestone timeline
Each milestone shows the exact calendar date and what to watch for. Completed milestones are highlighted.
4
Schedule vet appointments
Book ultrasound confirmation at day 25 to 30 and X-ray litter count at day 45 to 50 using the milestone dates.
Example
Bella, a Golden Retriever, was bred on March 10. What is her due date and when should her owner schedule the X-ray?
Mating dateMarch 10
Earliest (day 58)May 7
Due date (day 63)May 12
Latest (day 70)May 19
X-ray window (day 45+)April 24 onward
Whelp box ready by April 27 (day 48)
Common Mistakes to Avoid
!
Waiting for day 63 before preparing
Some dams whelp as early as day 58. Set up the whelping box and start temperature monitoring from day 55 to avoid being caught off guard.
!
Not confirming the litter count via X-ray
Knowing the puppy count before whelping helps you confirm when all puppies have been delivered. Retained puppies are a life-threatening emergency that require immediate veterinary care.
!
Skipping the day 25 ultrasound
Physical signs of pregnancy in dogs are often invisible until week 5 or 6. A day-25 ultrasound is the only reliable early confirmation method. Waiting too long to confirm means less time to prepare.
!
Assuming the temperature drop means immediate delivery
The temperature drop below 99°F signals whelping within 12 to 24 hours, not minutes. Stay close but do not panic if labor does not begin immediately after the drop.
Concannon, P.W.: Canine Pregnancy: Predicting Parturition and Timing Events of Gestation
Primary veterinary reference for the 63-day average gestation from LH surge, ovulation timing, and the normal day 58 to 70 whelping range.
2
Veterinary Information Network (VIN): Canine Reproduction and Obstetrics
Clinical reference for milestone timing including when ultrasound can confirm pregnancy, X-ray litter count windows, and pre-whelp temperature monitoring protocols.
S
Dr. Sarah Whitfield, DVM
Veterinarian, 8 years in small animal reproductive medicine and canine obstetrics
Sarah reviewed the gestation formula, milestone timing, and emergency warning signs on this page. She has managed canine pregnancies across dozens of breeds in both clinical and breeding kennel settings.
Gestation Quick Reference
Average gestation63 days
Normal whelping rangeDay 58–70
Ultrasound confirmationDay 25–30
X-ray litter countDay 45+
Whelping box setupDay 55
Temperature monitoringDay 55 onward
Pre-labor temp dropBelow 99°F
Labor starts after drop12–24 hours
Typical Litter Size by Size
Toy / Small (< 20 lbs)
1–4 puppies
Medium (20–50 lbs)
4–6 puppies
Large (50–90 lbs)
6–8 puppies
Giant (90+ lbs)
7–12 puppies
Confirm count with X-ray from day 45 onward.
Pro Tip
Take your dog's rectal temperature twice daily starting on day 55. Log each reading. A drop of 1°F or more below her personal baseline (not just below 99°F) is the most reliable pre-labor signal.