Cats are pregnant for about 65 days on average — roughly nine weeks, or a little over two months — with most queens delivering between days 63 and 67 after mating (MSD Veterinary Manual). This cat gestation calculator turns your cat’s mating date into an estimated due date, a realistic delivery window, and a timeline of milestones so you know what to watch for and when.
The number the calculator uses
The tool adds your chosen gestation length to the mating date. It defaults to 65 days, the widely accepted average: the MSD/Merck Veterinary Manual reports delivery typically 64–66 days after breeding, and a University of Minnesota feline colony study measured an average of 66.9 days across monitored pregnancies (Root Kustritz et al., PubMed). Because conception timing is rarely exact, the calculator also shows the typical 63–67 day window rather than a single fixed date.
How long are cats pregnant?
The short answer: a cat’s pregnancy lasts about 63 to 67 days, averaging 65. The full possible range runs wider — the Merck Veterinary Manual gives 58–72 days when counted from breeding (and 62–64 days when counted precisely from ovulation), because cats are induced ovulators and may mate over two or three days (Merck Veterinary Manual). In practical terms, most house cats and pedigree breeds carry their litters for around nine weeks, and gestation length varies little by breed. The average litter is about four kittens, though litters of one to eight or more are common.
If your cat passes day 67 with no signs of labor, keep watching closely; if she reaches roughly day 71–72 or seems unwell at any point, call your vet.
Cat gestation timeline & due-date chart
The table below maps a mating date to its 65-day due date and the 63–67 day window, so you can sanity-check the calculator or plan ahead.
| Mating date | Window opens (day 63) | Due date (day 65) | Window closes (day 67) |
|---|---|---|---|
| Jan 1 | Mar 5 | Mar 7 | Mar 9 |
| Mar 1 | May 3 | May 5 | May 7 |
| Jun 1 | Aug 3 | Aug 5 | Aug 7 |
| Sep 1 | Nov 3 | Nov 5 | Nov 7 |
| Nov 1 | Jan 3 | Jan 5 | Jan 7 |
Within that window, the pregnancy passes through recognizable stages: “pinking up” of the nipples around days 16–20, heartbeats visible on ultrasound from about day 21 (best imaged at 25–35 days), a visibly rounder belly near day 30, and skeletal calcification that lets a vet count kittens on X-ray after about day 55 (PetMD).
How to use the cat gestation calculator
- Enter the mating / breeding date. If your cat mated over several days, use the first day.
- Leave the gestation length at 65 days (the average), or switch to 63 or 67 to see the edges of the typical window.
- Read your estimated due date, the delivery window, and the days-to-go countdown.
- Check the milestone list for the dates to expect pinking up, ultrasound, and X-ray.
- Use Print / save to keep a copy for your records or your vet.
Cat Gestation Calculator
Enter the mating date to estimate your cat's due date, delivery window, and key pregnancy milestones.
Key pregnancy milestones
Cat gestation reference table & chart
| Source | Average | Typical range |
|---|---|---|
| MSD / Merck Vet Manual (owner) | ~65 | 64–66 |
| Univ. of Minnesota colony study | 66.9 | 62–71 |
| Merck Vet Manual (from breeding) | — | 58–72 |
| PetMD / PMC review | 63–65 | up to 72 |
Frequently asked questions
How long do cats stay pregnant?
About 63–67 days, averaging 65 — roughly nine weeks. The full range from mating can span 58–72 days.
How long does it take cats to have kittens once labor starts?
Once active labor begins, most cats deliver the whole litter within about four to six hours, with kittens arriving from 10 minutes to an hour apart.
What is the gestation period for cats in weeks and months?
Around nine weeks, or a little more than two months.
Can I know my cat’s exact due date?
Only approximately. Cats can mate over several days and are induced ovulators, so conception timing is fuzzy. A vet can narrow it with ultrasound (best at 25–35 days) or X-ray after about day 55.
Does breed change the cat gestation period?
Not meaningfully. Length is similar across house cats and pedigree breeds; litter size and individual variation matter more.
When should I worry about a late delivery?
Watch closely past day 67, and contact your vet if your cat reaches roughly day 71–72 or shows any signs of illness or distress.
Sources
- MSD / Merck Veterinary Manual — Management of Reproduction of Cats: msdvetmanual.com
- Merck Veterinary Manual — Reproductive System in Animals (gestation table): merckvetmanual.com
- Root Kustritz et al., University of Minnesota — feline gestation & litter data: pubmed.ncbi.nlm.nih.gov
- Clinical management of pregnancy in cats (review): pmc.ncbi.nlm.nih.gov
- PetMD — Cat Pregnancy: Signs, Stages and Care: petmd.com
Reviewed for accuracy against the MSD/Merck Veterinary Manual and peer-reviewed feline reproduction literature. Last updated: July 16, 2026.
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