Cat Pregnancy Calculator Kitten Due Date & Week-by-Week Tracker
Find out when your cat’s kittens are due, how far along she is and which vet milestones are coming up. Work it out from the mating date, several matings, your vet’s estimate, or just the signs you can see.
By Manzoor Ahmad · Updated October 18, 2026
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Kittens due around
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Enter a date to see her due date
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Her pregnancy milestones
Week-by-week dates
| Week | Dates | What’s happening |
|---|
How long are cats pregnant?
Cats are pregnant for about 63 to 65 days, roughly 9 weeks. Queens (female cats) ovulate in response to mating, and the Merck Veterinary Manual places birth 64–66 days after the hormone surge that mating triggers. Most kittens arrive between day 61 and day 70 after mating. Kittens born before about day 58 are usually premature, and a queen still pregnant after day 70 should see a vet.
How to use the cat pregnancy calculator
- Choose a dating method. If you saw the mating, use that date. If she was with a tom for several days, use “Several matings”. No idea? Choose “I don’t know”.
- Enter the date or sign. The sign-based estimate gives a wider window. A vet ultrasound narrows it a lot.
- Read her milestones. See when to book an ultrasound, when an X-ray can count kittens and when to set up the nesting box.
- Save the timeline. Tap “Add to calendar” to put every milestone and her due date on your phone.
Due date = mating date + 65 days (normal window: day 61–70)
Several matings: first mating + 61 to last mating + 70
Vet estimate: scan date − days pregnant + 65
Cat pregnancy week by week
Cat pregnancy has three “trimesters” of about three weeks each. Not much shows on the outside until week 3, and the biggest changes come in the final three weeks.
| Week | Inside | What you’ll see | What to do |
|---|---|---|---|
| Week 1 (days 1–7) | Ovulation and fertilization | Heat behavior fades | Keep her indoors and away from other toms |
| Week 2 (days 8–14) | Embryos reach the uterus and implant | Usually nothing | No new medicines or flea products without your vet |
| Week 3 (days 15–21) | Heartbeats become visible on ultrasound | “Pinking up”: nipples turn pink and enlarge. Possible mild vomiting. | Book a vet visit to confirm pregnancy |
| Week 4 (days 22–28) | Kittens can be felt as small lumps by a vet | Appetite starts rising | Ask about switching to a kitten (growth) food |
| Week 5 (days 29–35) | Organs form, rapid growth | Belly rounding, weight gain | Offer more frequent, smaller meals |
| Week 6 (days 36–42) | Skeletons begin to mineralize | Obvious belly, more affectionate or more withdrawn | Keep play gentle, with no jumping from heights |
| Week 7 (days 43–49) | Kittens visible on X-ray from about day 45 | Kitten movements may be visible | X-ray to count kittens, prepare a nesting box |
| Week 8 (days 50–56) | Kittens near full size, fur forming | Searching closets for a nest, mammary glands enlarge | Put the nesting box in a quiet, warm spot |
| Week 9 (days 57–65+) | Ready for birth | Restlessness, panting, milk, loss of appetite 12–48 h before | Stay close and keep your vet’s emergency number handy |
How to tell how far along your cat is
Don’t know when she mated? Visible signs give a rough age. The “I don’t know” option in the calculator uses these ranges:
| Sign | Approximate day of pregnancy | Days left to birth |
|---|---|---|
| Nipples “pink up” | ~15–21 | ~44–50 |
| Belly starts rounding, appetite up | ~28–35 | ~30–37 |
| Clearly swollen belly | ~35–45 | ~20–30 |
| Kittens moving | ~45–55 | ~10–20 |
| Nesting, milk, restlessness | ~56–64 | ~1–9 |
For a precise date, a vet ultrasound can measure the kittens. Heartbeats are usually visible from around day 16–22, and fetal head size helps estimate age later in pregnancy.
How vets confirm cat pregnancy
There’s no reliable at-home or hormone pregnancy test for cats. Vets use these tools instead:
Ultrasound · from ~day 16–22
The earliest reliable method. It shows gestational sacs and heartbeats, and checks that the kittens are alive. It isn’t good for counting them.
Palpation · weeks 3–4
A vet can gently feel the uterine swellings at around 3–4 weeks. Please don’t press on her belly at home, because it can harm the pregnancy.
X-ray · from ~day 45
Kitten skeletons show up once they mineralize. A late X-ray is the best way to count kittens, so you’ll know when she’s finished.
How many kittens will my cat have?
The average litter is about 4 kittens, with a normal range of 1 to around 10. First-time and very young or older queens often have smaller litters. Some Oriental breeds tend to have larger ones. An X-ray in the last two to three weeks gives the real count.
Labor in cats (queening): what’s normal and what’s not
Stage 1 · 12–48 h
Restlessness, pacing, panting, nesting, loud purring or vocalizing, and refusing food. First-time mothers may seem anxious.
Stage 2 · delivery
Visible contractions and pushing. Once a head or feet appear, the kitten usually arrives within minutes. Labor totals about half a day on average, from 4 hours to 2 days.
Stage 3 · placentas
A placenta follows each kitten. She may eat them, which is normal. Count them if you can.
Call your vet right away if she:
- Strains hard for 20–30 minutes without producing a kitten, or a kitten is stuck in the birth canal
- Rests for more than 1–2 hours between kittens while clearly straining or distressed, with more kittens expected
- Has green, black or heavy bloody discharge before the first kitten
- Passes day 70 with no labor
- Is weak, collapses, has a high or low temperature, or seems exhausted
- Trembles, pants heavily or wobbles while nursing in the weeks after birth. These are signs of eclampsia (milk fever), which is an emergency.
Worked example: Mochi, mated on March 1, 2026
- Due date: March 1 + 65 days = Tuesday, May 5, 2026. Normal window: May 1 – May 10.
- Ultrasound: heartbeats visible from about March 17–23 (days 16–22).
- X-ray kitten count: from about April 15 (day 45).
- Nesting box ready: by around April 20 (day 50).
- Call the vet if: no labor by May 10 (day 70).
Caring for a pregnant cat: a pharmacist’s safety notes
- Never give acetaminophen (Tylenol). Cats can’t break it down, and even a fraction of one tablet can be fatal, pregnant or not.
- Check flea products carefully. Dog spot-ons containing permethrin can kill cats. Only use pregnancy-safe products your vet recommends.
- Skip calcium supplements during pregnancy unless your vet prescribes them. A good kitten food covers her needs, and extra calcium can upset her own regulation around birth.
- Keep lilies and allium foods out of reach. Lilies cause kidney failure in cats, and cats are the most sensitive species to onion and garlic.
- Feeding: many vets suggest switching gradually to a kitten (growth) diet in the second half of pregnancy and letting her eat more often. Her energy needs keep climbing into nursing.
Related pet calculators
Plan the next steps for her and the kittens:
Cat pregnancy calculator FAQs
About 63 to 65 days, or 9 weeks. Most kittens are born between day 61 and day 70 after mating. Before about day 58 kittens are usually premature, and after day 70 she should see a vet.
Add 65 days to the mating date. For example, a cat mated on March 1 is due around May 5, with a normal window from about May 1 to May 10. If she mated over several days, the window runs from 61 days after the first mating to 70 days after the last.
Pink, enlarged nipples suggest about 2.5–3 weeks. A rounding belly suggests 4–5 weeks. Visible kitten movement suggests 6.5 weeks or more, and nesting with milk suggests the last week. A vet ultrasound gives a more precise estimate.
The first visible sign is usually “pinking up” around weeks 2–3, when the nipples turn pink and enlarge. The belly usually starts to round out around weeks 4–5.
There’s no reliable home test, and human pregnancy tests don’t work on cats. Vets confirm pregnancy by ultrasound (heartbeats from around day 16–22), palpation at 3–4 weeks, or X-ray from about day 45.
About 4 on average, with a range of 1 to around 10. First litters are often smaller. An X-ray late in pregnancy gives an accurate count.
In the 12–48 hours before birth she may pace, pant, nest, vocalize, groom her belly and refuse food. Milk may appear on her nipples in the last few days.
Delivering a whole litter takes about half a day on average, ranging from roughly 4 hours to 2 days. Once a kitten is visible it should arrive within minutes. Call your vet if she strains for 20–30 minutes with no kitten.
Yes. Queens can come back into heat within weeks of giving birth, even while nursing. Keep her away from intact males and talk to your vet about spaying once the kittens are weaned.
Many cats reach puberty at around 4–6 months, sometimes earlier. Early spaying, or keeping young females away from intact toms, prevents accidental litters.
A complete kitten (growth) food is commonly recommended from the second half of pregnancy through nursing, offered in smaller, more frequent meals. Avoid supplements, especially calcium, unless your vet prescribes them.
If she’s more than 70 days past mating with no labor, call your vet. If you’re unsure of the mating date, an X-ray or ultrasound can show how developed the kittens are.
Manzoor Ahmad
Pharmacist & health writer · 13+ years of web development and SEO experience
Manzoor is a pharmacist with more than nine years of experience writing evidence-based health and supplement content. He builds every dexocalc pet calculator from primary veterinary references. The gestation length, milestones and labor guidance in this tool follow the Merck Veterinary Manual, university extension guidance on feline pregnancy and published feline ultrasound research. This calculator supports planning. It does not replace your veterinarian.
Sources
- Davidson AP. Whelping and Queening in Dogs and Cats. Merck Veterinary Manual (revised June 2025).
- Sharma D. Basics of Pregnancy and Birth in the Cat. Rutgers University / Extension.
- Wardhana AW, et al. Correlation of Gestational Sac, Fetal Heart and Fetal Head Diameter to Gestational Age in Cats. ICAMBBE 2019 (SciTePress, 2020).
Disclaimer: This cat pregnancy calculator provides educational estimates based on average feline gestation. Individual cats vary, and sign-based estimates are approximate. Always confirm pregnancy and plan for birth with a licensed veterinarian, and contact one immediately if you notice any warning sign during pregnancy or labor.