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Dog Pregnancy & Whelping Due-Date Calculator
Get an accurate whelping date from the ovulation, LH surge, or breeding date, plus the ultrasound, X-ray litter-count, and temperature-monitoring windows. Anchoring to ovulation is far more reliable than the “mating date plus 63” shortcut most calculators use.
Pregnancy details
Anchor to ovulation for the most accurate date. Don’t have a date? The progesterone calculator finds your ovulation day from blood tests.
The day progesterone reached ~5 ng/mL (from your progesterone tests). This gives the most accurate due date.
Saved on this device only, nothing is uploaded. Update the date as your timing is confirmed.
Enter a date to see the due date & care timeline
Pick what you know, ovulation, the LH surge, or the breeding date, and add the date on the left.
The timeline
Nine weeks, day by day
Canine gestation is short and predictable when you count from ovulation. Each milestone below is timed from the day the eggs are released (P4 ≈ 5 ng/mL), the same anchor the calculator uses.
Ovulation
Day 0Eggs are released about 2 days after the LH surge, then mature for ~2 more days before fertilization. This is the anchor for everything that follows.
Ultrasound, confirm pregnancy
Day 25-30Fetal heartbeats are visible from ~day 21-25; day 25-30 confirms pregnancy and viability. A relaxin blood test is also reliable around now.
Radiograph, count the litter
Day 50-58Fetal skeletons are mineralized and countable. Knowing the number of puppies tells you when whelping is complete.
Begin temperature monitoring
Day 58+Take the dam's temperature 2-3× daily. A drop below ~99°F (37.2°C) means whelping within ~24 hours.
Whelping (± 1 day)
Day 63Gestation averages 63 days from ovulation (≈65 from the LH surge). Litter size and breed shift the day slightly.
Methodology & sources
Built on established protocols
The gestation lengths and imaging windows are drawn from peer-reviewed canine theriogenology and major veterinary references, cross-checked across sources. This tool is educational and does not replace your veterinarian.
- De Cramer KGM. Simplifying the Canine Reproductive Cycle Using the Concentration of Progesterone (IDEXX, 2019), gestation length from ovulation and the LH surge.
- Merck Veterinary Manual, Pregnancy Determination in Bitches and Queens; Management of Reproduction (ultrasound and radiograph timing).
- American Kennel Club, canine gestation length and pregnancy milestones.
- WSAVA, Breeding Management and Ovulation Timing in the Bitch.
- Today's Veterinary Practice, Imaging Essentials: Fetal Count Radiology (radiograph litter count from ~day 55).
Important: A calculated date is an estimate, not a guarantee. The most accurate due date comes from progesterone-confirmed ovulation; a date counted from a single mating can be off by a week. Confirm pregnancy, litter count, and whelping or C-section timing with a reproductive veterinarian.
Frequently asked questions
Keep exploring
Related tools and guides
Know the due date? These tools cover what happens next, from nutrition and whelping prep to puppy health records.
From breeding to whelping, in one place
BreedTracker counts every due date for you, sends whelping reminders, and keeps ultrasound, X-ray, and puppy records together for each litter, so nothing slips through the cracks at 2 a.m.
Free for up to 4 litters a year · No credit card required