Cat Pregnancy Calculator

How to use the Cat Pregnancy Calculator#

1. Enter the breeding date. Use the date of mating, or of insemination.
2. Check the length. Leave the average, or enter your vet’s figure for the breed.
3. Read your dates. You get the expected date, the likely window and your cat’s progress.

How long is a cat pregnant?#

Most cats give birth about 63 to 67 days after mating, with 65 as a common midpoint. If she was mated several times over a few days, use the first date and treat the end of the window with care.

Getting ready for the kittens#

A few weeks before the due date, set up a quiet, warm, draught-free box in a room she likes. Many queens look for a hidden place in the final days, so offering a choice can help. Keep fresh water and good-quality food close by, and ask your vet which diet suits a pregnant or nursing cat.

Know your vet’s emergency number. Call at once if labour seems stuck, if she has strong contractions for a long time with no kitten, or if she seems unwell.

Why the date is a window#

The usual range for a cat is only four days wide, 63 to 67, so the date is fairly dependable once you know the mating day. The uncertainty is at the start. Queens often mate over two or three days, so use the first date and expect the later end of the window. If she is still waiting after day 67, ring your vet. This calculator is a planning tool and doesn’t replace veterinary advice.

A worked example#

Say a queen was mated on Fri 12 March 2027. With the default 65 days, the calculator gives Sun 16 May 2027 as the due date. The likely window runs from Fri 14 May 2027 (day 63) to Tue 18 May 2027 (day 67). The halfway point lands on Wed 14 April 2027, and the final stretch, which the calculator counts from 85 percent of the term, begins on Thu 6 May 2027.

Write the window on a calendar rather than just the single date. Kittens that arrive on day 63 are not early in any worrying sense, and a queen who reaches day 66 is not late.

Why the mating date is a good starting point for cats#

A cat’s ovulation is triggered by mating itself, so counting from the day she was mated usually gives a tighter estimate than the same count does in a dog. That is the main reason the cat window is only four days either side of the average, while some other species have a much wider spread.

The catch is that queens often mate repeatedly over two or three days, sometimes with more than one tomcat, and a single litter can have kittens from different fathers. If you did not see the first mating, count from the day you first noticed the calling and rolling behaviour, then expect the later end of the window.

Signs and checks during the nine weeks#

Around the third week her nipples usually turn a deeper pink and look slightly enlarged, which breeders call pinking up. A vet can often feel or see the pregnancy by ultrasound at about three weeks, and an X-ray taken after the skeletons have formed, from roughly day 45, is the usual way to count how many kittens to expect.

Her belly rounds out in the second half, her appetite climbs, and in the last few days she may eat less and start searching for a hiding place. Check with your vet about food during pregnancy, because many recommend switching to a kitten formula, which is higher in energy and protein.

Mark day 55 on your calendar (Thu 6 May 2027 in this example). From that point have the nesting box ready and keep the clinic’s out-of-hours number somewhere you can find it quickly.

When to call the vet before the due date#

Do not wait for the window to close if something looks wrong earlier. A green or bloody discharge before any kitten has appeared, a queen who is weak or vomiting repeatedly, or labour that starts well before day 60 all deserve a same-day call. Kittens born before about day 58 rarely survive, so early labour is worth treating as urgent, and a vet may be able to help her hold off.

Last reviewed October 2026 by the Calclulo team.