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Dog Pregnancy Calculator

Enter the mating date to see the expected whelping date, a full 9-week gestational timeline with key milestone dates, and an estimated litter size for your dog's breed size.

Canine Gestation: 9-Week Stage Breakdown

The average canine gestation is 63 days from ovulation (LH surge), with a normal whelping range of 58–68 days. Here is what happens each week:

WeekDaysMilestoneWhat's happening
Week 1Days 1–7FertilizationMating and fertilization occur. Zygotes begin dividing. No visible signs in the dam.
Week 2Days 8–14Cell divisionEmbryos travel toward uterus. Possible mild nausea. No external signs yet.
Week 3Days 15–21ImplantationEmbryos implant in uterine wall (day 17–21). Nipples begin to pink. Slight appetite changes.
Week 4Days 22–28Confirmation possibleVet can confirm via ultrasound/palpation. Fetal heartbeats visible. Increase food 10%.
Week 5Days 29–35Rapid developmentToes and claws form. Weight gain noticeable. Increase food 25%. Moderate exercise only.
Week 6Days 36–42Visible pregnancyAbdomen clearly enlarged. Puppies can be felt moving (late). X-ray possible from day 42.
Week 7Days 43–49Nesting beginsSet up whelping box. Mammary glands developing. Hair loss around nipples. Feed 75% above normal.
Week 8Days 50–56Pre-whelpingTake temperature 2×/day. Visible puppy movement. Milk production starts. Have vet number ready.
Week 9Days 57–63+WhelpingTemperature drop below 37.8°C signals labor within 24 hours. Puppies fully developed and ready.

How Long Are Dogs Pregnant?

Canine gestation formula:

63 days from LH surge (range: 58–68)

Dogs are pregnant for approximately 9 weeks. The 63-day mean is measured from ovulation (the LH surge), not from mating. Mating can happen days before or after ovulation, so gestation counted from the mating date appears to range from 56 to 72 days.

  • 1Ovulation occurs 2 days after the LH surge. Fertile eggs are available for 48–72 hours after ovulation.
  • 2Canine sperm survive 5–7 days in the female reproductive tract — breeding before ovulation still results in pregnancy.
  • 3The wide 58–68 day range accounts for biological variation in implantation timing and litter size. Larger litters tend to deliver a day or two earlier; smaller litters may go slightly longer.
  • 4Breed size has a small but real effect: small breeds tend toward the shorter end (61–62 days from mating), while giant breeds often go 64–65 days. The 63-day mean holds across all sizes.
  • 5Progesterone testing by your vet is the most accurate way to pinpoint ovulation day, making due date prediction ±2 days accurate.
  • 6If your dog has not whelped by day 70 from the last mating (or day 68 from confirmed ovulation), contact your vet immediately.

Average Litter Size by Breed Size

Breed sizeExample breedsAverage litterNote
Small (under 10 kg)Chihuahua, Pomeranian, Yorkie, Maltese1–4Often 2–3 in first litter
Medium (10–25 kg)Beagle, Cocker Spaniel, Border Collie4–8Most common range across breeds
Large (25–45 kg)Labrador, Golden Retriever, German Shepherd6–10Labs average 7–8
Giant (over 45 kg)Great Dane, Mastiff, Saint Bernard8–14Record litters 15+

Pregnancy Journey Guides

From first signs to newborn care, follow the full canine pregnancy journey:

→What happens each week of dog pregnancy — stages and symptoms→How to confirm dog pregnancy: home tests, vet checks, and false pregnancy→How much to feed a pregnant dog at each stage of gestation→Whelping box setup and birth preparation checklist→Signs a dog is going into labor — and when to call the vet→Newborn puppy care — week-by-week guide for the first 4 weeks→When to wean puppies and how to introduce solid food→Puppy development stages — growth milestones from birth to 8 weeks

Feed your pregnant dog the right amount

Around day 30, switch to a high-quality puppy food. It has the extra protein, calcium, and calories needed for fetal development and milk production. Increase portions gradually: about 25% above normal by week 6, and up to 50 to 75% more by the final week. The dog food calculator gives exact daily amounts in grams and cups for your dog's weight and food type.

Dog food calculator — get daily feeding amounts →

Whelping Supplies Checklist

Have everything ready at least two weeks before the due date. Scrambling for supplies during active labor adds stress you don't need.

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Whelping box

Large enough for dam to stretch fully; set up by week 7

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Clean towels & blankets

For drying puppies and lining the box; have extras

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Heat lamp or heating pad

Newborns can't regulate temperature; keep area 29–32°C

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Digital rectal thermometer

For twice-daily readings from day 55; watch for drop below 37.8°C

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Puppy scale

Weigh each pup daily; steady gain confirms feeding is working

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Sterile scissors & dental floss

To tie and cut umbilical cords if dam doesn't

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Iodine solution

Apply to umbilical cord stumps to prevent infection

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Puppy milk replacer & bottles

In case dam can't nurse; have on hand before whelping

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Sterile gloves

For assisted delivery if needed

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Emergency vet contact

Have the number visible — you may need it at 2am

First-time mothers need closer monitoring

Dogs having their first litter are more likely to need help during delivery and have higher rates of labor complications than experienced mothers. If this is your dog's first pregnancy, schedule weekly vet visits from day 50 onward and talk to your vet about C-section risk beforehand, particularly for brachycephalic or small breeds.

Frequently Asked Questions

The calculator uses the 63-day mean gestation period from ovulation (LH surge), which is the standard reference in veterinary reproductive medicine. When only a mating date is available, accuracy is roughly plus or minus 5 days, because ovulation does not always coincide with breeding. If you have a confirmed LH surge or ovulation date from progesterone testing, accuracy improves to plus or minus 2 days. The normal whelping range is day 58 to 68 from the LH surge.
Dogs are pregnant for approximately 63 days (9 weeks) from ovulation. The normal gestation range is 58 to 68 days from the LH surge. When counting from the mating date rather than ovulation, the apparent gestation can look like 56 to 72 days, because sperm can survive 5 to 7 days in the reproductive tract and ovulation timing varies relative to when mating occurred.
Litter size depends mainly on breed size. Small breeds average 1 to 4 puppies, medium breeds 4 to 8, large breeds 6 to 10, and giant breeds 8 to 14. First litters tend to be smaller than later ones. Other factors include the dam's age, health, nutrition, and how close breeding was to ovulation. The largest recorded litter was 24 puppies, born to a Neapolitan Mastiff in 2004.
Plan three visits: day 25 to 28 for pregnancy confirmation via ultrasound or relaxin blood test, which is the earliest reliable window; day 42 to 45 for an X-ray puppy count, since fetal skeletons are visible on radiograph from day 42 and give you an accurate number so you know when whelping is finished; and day 50 to 55 for a pre-whelping check on puppy positioning and birth planning. For first-time mothers, add weekly check-ups from day 50 onward. During labor, call your vet right away if your dog strains for more than 30 minutes without producing a puppy, more than 4 hours pass between puppies with no contractions, you see bright green or black vaginal discharge before the first puppy is born (some green-black fluid after the first puppy is normal), the dam collapses or loses consciousness, or her temperature drops below 37.8°C but labor does not start within 24 hours.
The earliest physical signs typically appear around weeks 3 to 4: slightly pinker or enlarged nipples, mild appetite changes or brief nausea, and a clear vaginal discharge. Behavioral changes like increased affection or seeking quiet spots may appear earlier, but they are not reliable indicators. The only way to confirm pregnancy before visible signs is a relaxin blood test (accurate from day 26 to 28) or ultrasound (from day 25). You cannot confirm pregnancy by observation alone before week 4.
False pregnancy (pseudopregnancy) happens when a female dog shows physical and behavioral signs of pregnancy without actually being pregnant. It affects roughly 50 to 75 percent of intact females at some point in their lives, triggered by the normal drop in progesterone after a heat cycle. Signs include enlarged mammary glands, milk production, nesting, weight gain, and mothering toys, all of which look identical to a real pregnancy. The main difference is that false pregnancy resolves on its own within 2 to 3 weeks without treatment. A relaxin blood test or ultrasound from your vet is the only reliable way to tell them apart. Do not try to diagnose false versus real pregnancy based on outward signs.
Set up the whelping box by day 42 to 49 (week 7) at the latest. The dam needs at least two weeks to get comfortable in the space before labor. Place it somewhere quiet and warm, away from household traffic. The box should be large enough for the dam to lie fully stretched out with 6 to 8 inches of extra space on each side, with sides tall enough to keep puppies in but low enough for the dam to step over. Stock it ahead of time: clean towels, a heat lamp or heating pad (newborns cannot regulate their own temperature), a digital rectal thermometer for twice-daily readings from day 55 onward, a puppy scale, iodine for umbilical cord care, and your vet's emergency number. Starting around day 55 to 58, take your dog's rectal temperature twice daily at the same times. Normal canine temperature is 38 to 39°C (100.4 to 102.2°F). When it drops below 37.8°C (100°F) and stays there, labor usually begins within 12 to 24 hours.
The mating date is when breeding occurred. The ovulation date (LH surge) is when eggs were released, and this is what actually determines how long the pregnancy lasts. Dogs can be bred days before or after ovulation and still conceive, because canine sperm survives up to 7 days and eggs remain viable for 48 to 72 hours after release. This is why gestation counted from the mating date appears variable (56 to 72 days), while gestation measured from ovulation is consistently 63 days, plus or minus 2.
About 5 to 10 percent of all dog births require cesarean intervention. The rate varies dramatically by breed: brachycephalic breeds such as French Bulldogs, English Bulldogs, and Boston Terriers have C-section rates of 80 to 90 percent because the puppies' heads are large relative to the dam's birth canal. Other higher-risk breeds include Scottish Terriers, Clumber Spaniels, and Mastiffs. If you have a breed in any of these categories, discuss C-section planning with your vet before the due date.

Related Tools & Guides

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Dog Food Calculator

Get daily feeding amounts for your pregnant dog by food type and weight.

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Dog Calorie Calculator

Calculate daily calorie needs — includes pregnancy adjustments.

About This Calculator

The PawToolkit Dog Pregnancy Calculator uses the 63-day mean gestation from the LH surge, established in canine reproductive physiology research by Concannon (2011, Animal Reproduction Science). The 58 to 68 day whelping window represents plus or minus one standard deviation from the mean, covering approximately 95% of normal canine gestations.

Litter size estimates are based on breed-size averages from Borge et al. (2011, PLOS ONE), which analyzed over 10,000 litters across 224 breeds. Individual variation is large: dam age, parity, nutrition, and timing of breeding relative to ovulation all affect litter size.

The gestational stage descriptions are drawn from Johnston, Root Kustritz & Olson (Canine and Feline Theriogenology, Saunders 2001), the standard veterinary reproduction textbook used in clinical training worldwide.

PawToolkit provides general educational information only and is not a substitute for veterinary advice. Always consult a licensed veterinarian for medical decisions about your pregnant dog, including complications, C-section planning, and high-risk breeds.