Cat Pregnancy Calculator (2026)
Enter your cat’s mating date to get her due date, safe delivery window, and vet check milestones.
When Is My Cat Due?
The date your cat mated. If you only know an approximate date, use your best estimate and treat the result as a range, not an exact day.
Vet milestones
The Formula
Cat gestation averages 63 to 65 days, so this calculator uses 65 days from mating as the expected due date and shows the full normal window around it. A cat that delivers a few days either side of the due date is usually still within normal range, which is why the window matters more than any single day.
Earliest normal delivery = mating date plus 60 days
Latest normal delivery = mating date plus 70 days
Ultrasound from = mating date plus 25 days
X-ray for kitten count from = mating date plus 45 days
Nesting prep from = mating date plus 58 days
Worked example: a mating date of January 1, 2026 gives a due date of March 7, 2026, with a normal window of March 2 to March 12, 2026. The ultrasound milestone falls on January 26, 2026, the X-ray milestone on February 15, 2026, and nesting prep starts on February 28, 2026.
Cat Pregnancy Week by Week
| Week | What is happening | What to do |
|---|---|---|
| Week 1 (days 1-7) | Fertilisation and early embryo development; usually no visible signs. | Keep feeding normally; avoid unnecessary medication and stress. |
| Week 2 (days 8-14) | Embryos implant in the uterus; appetite may dip briefly. | Offer small, frequent meals if she seems off her food. |
| Week 3 (days 15-21) | Nipples often turn pink and slightly enlarged, called pinking up. | Book a vet check if you have not already; confirm the pregnancy. |
| Week 4 (days 22-28) | Morning sickness can appear; belly starts to firm up. | Ultrasound is possible from about day 25 to confirm kittens. |
| Week 5 (days 29-35) | Belly visibly grows; appetite usually increases. | Move to a high-quality kitten or pregnancy diet on vet advice. |
| Week 6 (days 36-42) | Kittens grow fast; weight gain becomes obvious. | Feed more often in smaller portions as her stomach is squeezed. |
| Week 7 (days 43-49) | Kittens are nearly formed; movement may be felt. | X-ray from day 45 can count kittens; keep her indoors. |
| Week 8 (days 50-56) | She rests more and grooms her belly; nesting behaviour starts. | Set up the kittening box in a quiet, warm spot. |
| Week 9 (days 57-65) | Final growth; milk may appear; she may go off food near labour. | Watch closely from day 60; keep the vet number handy. |
Signs Your Cat Is Pregnant
The earliest reliable sign is usually pinking up: around week 3 the nipples become pinker and slightly swollen. After that, watch for a growing belly, increased appetite from about week 5, weight gain, more affection or, in some cats, more withdrawal, and nesting behaviour in the final weeks. No single sign proves pregnancy on its own, and a false pregnancy or weight gain can look similar, so a vet check is the only way to be sure.
Behaviour changes alone are easy to misread. A cat that sleeps more, eats more, and seeks attention may simply be settling into a routine change. Combine what you see with the dates: if mating happened 3 to 4 weeks ago and her nipples have pinked up, pregnancy is likely, and an ultrasound from day 25 can confirm it.
Kittening Box Prep
Set the box up by about day 58 so your cat can get used to it before labour. Choose a sturdy cardboard box or a whelping box with low sides she can step over, lined with clean towels or newspaper that you can change easily. Place it somewhere quiet, warm, and draught-free, away from other pets and household traffic, and let her explore it without forcing her in. Some cats will still choose their own spot, often a wardrobe or a quiet corner, so have a backup plan and do not be surprised if she relocates.
- Clean bedding: fresh towels, changed after birth and whenever soiled.
- Warmth: a warm room; newborn kittens chill quickly, so avoid cold floors.
- Food and water nearby: she may not want to leave the kittens for long.
- Privacy: keep visitors and other pets away during and after birth.
- Vet number on hand: written down where anyone helping can find it.
When to Call the Vet
Call your vet promptly if labour lasts more than a few hours with strong straining and no kitten, if more than 2 hours pass between kittens with continued straining, if she shows heavy bleeding, foul discharge, fever, vomiting, or collapse, or if she goes past day 70 with no signs of labour. Also call sooner if she stops eating for more than a day in late pregnancy, seems in pain, or you are unsure whether labour has started. These are warning signs, not a checklist to wait through: a quick call costs nothing and can save kittens.
Routine vet contact matters too. A pregnancy confirmation visit, an ultrasound from day 25, and an X-ray from day 45 for a kitten count help your vet plan for delivery and spot problems early, such as a very large litter or a kitten that may be too big. Tell your vet the mating date you used here so the dates line up with their checks.
