CollarCat Pregnancy, Gestation & Due Date Calculator
Is your cat expecting? Estimate her due date and kittening window from the mating date, and follow a week-by-week guide through her roughly 9-week pregnancy.
Cat Gestation Calculator
Enter the mating date to estimate her due date.
The Feline Gestation Period
A cat's pregnancy, or gestation, lasts about 63 to 65 days from mating, which is roughly 9 weeks. The natural range is about 60 to 67 days, and most cats deliver their kittens between day 63 and day 65.
Expected due date ≈ mating date + 63 to 65 days
Why the Mating Date Works for Cats
Cats are induced ovulators: the female releases eggs in response to mating, so ovulation and mating happen very close together. That is why the mating date is a reliable starting point for estimating the due date, and why cats do not have a separate fertile-window calculator the way dogs do.
Litter Size
A typical litter is about 3 to 5 kittens (averaging around four), though litters can range from 1 to 8 or more. Pedigree breeds such as Siamese, Oriental, and Burmese often have larger litters.
Note the mating date
Record the day your cat was mated.
Add about 63 to 65 days
Count forward roughly 9 weeks to the expected due date.
Prepare a nesting box
Set up a warm, quiet queening box about a week early.
Cat Pregnancy Week-by-Week
Follow the journey from mating to kittening, week by week, with what is happening and how to help her.
Fertilization
Days 1 to 7
Mating triggers ovulation, and the eggs are fertilized. There are no outward signs yet. Keep her calm and on her normal high-quality food.
Implantation
Days 8 to 14
The embryos travel to the uterus and implant. Still no visible signs. Continue her usual routine and avoid unnecessary medications.
Pinking Up
Days 15 to 21
Around day 16 to 20 her nipples become pinker and more prominent (“pinking up”), often the first visible sign. A vet may feel the kittens by gentle palpation.
Heartbeats
Days 22 to 28
Kitten heartbeats can be seen on an ultrasound at 3 to 4 weeks. Protect her belly and keep handling gentle.
Fetal Growth
Days 29 to 35
The kittens grow quickly and she begins to gain noticeable weight. Start offering a little more high-quality or kitten food.
Calcifying Bones
Days 36 to 42
The kittens' skeletons calcify and can show on an X-ray. Her belly is clearly rounded. Feed nutrient-dense food in smaller, frequent meals.
Big Appetite
Days 43 to 49
Her appetite peaks and her belly is large. Keep kitten food available and give her quiet, comfortable resting spots.
Nesting Begins
Days 50 to 56
Kittens are active and her mammary glands fill. She looks for a safe, hidden spot. Set up a warm, quiet queening box with soft bedding.
Kittening
Days 57 to 65
She becomes restless and may stop eating shortly before labor. Most queens give birth between day 63 and 65. Stay nearby and have your vet's number ready.
Frequently Asked Questions
Caring answers about your cat's pregnancy and kittening.
A cat is pregnant for about 63 to 65 days, roughly 9 weeks, counting from mating. The full range is about 60 to 67 days. Most cats deliver their kittens between day 63 and day 65.
One of the first signs is "pinking up" around day 16 to 20, when the nipples become pinker and more prominent. Later she gains weight, her belly swells, and her appetite grows. A vet can confirm the pregnancy with palpation from about 2.5 to 3 weeks or an ultrasound from 3 to 4 weeks.
A typical litter is about 3 to 5 kittens, with an average near 4. Litters can range from 1 to 8 or more, and pedigree breeds such as Siamese, Oriental, and Burmese often have larger litters.
A veterinarian can often feel the kittens by gentle palpation from about 2.5 to 3 weeks, detect heartbeats by ultrasound at 3 to 4 weeks, and count the kittens on an X-ray from about 6 weeks, once their skeletons have calcified.
Yes. "Feline" simply means cat, so this feline pregnancy calculator works the same way: it adds the average 63 to 65-day feline gestation period to the mating date to estimate her due date and kittening window.
Sources & Further Reading
The gestation figures on this page reflect published veterinary averages. To go deeper, visit these trusted references: