Enter the mating date and get the whole timeline — pregnancy check, due date, vaccinations and the earliest day the kittens can go to their new homes.
Adjust the defaults
These dates are a guide for planning. Queens can deliver a few days either side of the window, and your vet may advise a different vaccination or rehoming schedule. Always follow your vet’s and the GCCF’s current guidance.
How long are cats pregnant? Using the litter planner
A cat’s pregnancy is short and surprisingly precise. The average feline gestation period is about 65 days — roughly nine weeks — and most queens deliver somewhere in a 63 to 67 day window counted from the date of mating. Some perfectly normal litters arrive a touch earlier or later, but the count from mating is reliable enough to plan around with confidence. That predictability is exactly what makes a litter planner useful: enter the mating date and you can map the whole journey, from the first pregnancy check right through to the day the kittens are old enough to go to their new homes.
This guide explains every stage the planner calculates, why each date matters, and how to use the timeline to organise your own diary — time off work, holidays, and honest leaving dates for the families waiting on a kitten. It’s written from a GCCF breeder and judge’s perspective, but the biology applies to any breed of cat.
From calling to mating: where the count begins
Unlike dogs, queens are induced ovulators — they only release eggs in response to mating, and they call (come into season) repeatedly through the year rather than in one fixed breeding season. If you’re not yet sure your girl is ready, our guide to cats in season and what calling looks like walks through the signs, and going out to stud covers the mating visit itself.
The planner counts day zero from the mating date. Because queens are usually mated over two or three days, pick the first mating as your start point — the due-date window absorbs the small uncertainty. Mating itself triggers ovulation, so a queen mated repeatedly over a couple of days is simply making conception more likely; it does not move the due date by more than a day or two.
Confirming the pregnancy (around day 21)
The earliest reliable confirmation comes at about three weeks. From around day 21 a vet can gently palpate the abdomen, and an ultrasound scan can detect kittens from roughly the same point. You may also spot “pinking-up” — the nipples becoming pinker and more prominent — at around two to three weeks, often the first visible clue at home.
For the full picture of what to watch for and how a queen changes through pregnancy, see our detailed guide on how to tell if your cat is expecting kittens. The planner flags this ~day-21 check so it’s in your diary rather than left to chance.
The stages of cat pregnancy, week by week
Knowing roughly what is happening inside helps you give the right care at the right time. In the first three weeks, the embryos implant and begin to develop; outwardly your queen may seem much as usual, though some show early pinking-up and a few have a brief bout of “morning sickness”. During weeks three to five, pregnancy becomes detectable by a vet and the queen’s appetite starts to climb; her tummy begins to round out. From weeks five to seven the kittens grow rapidly, her abdomen becomes noticeably swollen, and she will be eating well above her normal ration — this is the time to be feeding a high-energy kitten food. In the final week or two she slows down, seeks out quiet corners, and starts looking for somewhere to nest. Providing a warm, private kittening box a week or two before the due date lets her settle in before the big day.
The due date and preparing for the birth
Count 65 days from mating for the estimated due date, and treat the 63–67 day band as the likely window. Have your kittening kit ready a week before the early end of that window — queens can surprise you, and first-time mums sometimes go a day or two early. A calm, warm, private nesting space set up well in advance makes all the difference. A sensible kit includes clean towels, a heat source the kittens can move away from, accurate kitchen scales, a notebook, your vet’s out-of-hours number, and the kittening box lined with disposable bedding.
Once the kittens arrive, enter the actual birth date in the planner. Everything after the birth — weaning, vaccinations and the leaving date — then recalculates from the real day rather than the estimate, so your schedule stays accurate. If you ever face orphaned or rejected kittens, our guide to tube feeding and hand-rearing is a practical lifeline.
Signs that labour is starting
In the day or so before labour, many queens go off their food and become restless and clingy, padding in and out of the nest. A classic sign is a drop in body temperature in the 24 hours or so before kittening. As labour approaches she may pant, vocalise, wash herself intensively around the rear, and start visible contractions. Most cats deliver calmly and capably on their own, and the best thing you can usually do is stay quietly nearby and let her get on with it. Do, however, know when to call the vet: prolonged, hard straining without producing a kitten, an obvious kitten stuck, heavy fresh bleeding, a foul discharge, or a queen who is exhausted or distressed all warrant a prompt call. Having the number to hand — part of your kittening kit — means you are not scrabbling for it at 3am.
The first 48 hours after birth
The hours just after birth matter enormously. Each kitten should be nursing within an hour or two: that first milk, the colostrum, is rich in the antibodies that give newborns their early protection, and the window to absorb it is short. Keep the nest warm — newborn kittens cannot regulate their own temperature and chill easily — and make sure every kitten is latching on and feeding. Weigh each kitten at birth and then daily, noting the figures; healthy kittens gain steadily from day one, and the scales are your early-warning system. A kitten that fails to gain, feels cold, or is pushed out by the others is the one to watch, as a fading kitten can go downhill quickly. Quiet observation, warmth and daily weights are the three things that get a litter safely through its first couple of days.
Weaning: from around four weeks
Weaning usually begins at about four weeks and is generally complete by eight to ten weeks. Kittens start to take an interest in solid food as the queen naturally begins to limit nursing; you introduce a suitable kitten weaning food alongside continued feeding from mum. First worming typically falls around this time too. Our full week-by-week guide to weaning kittens walks through how to do it properly, and our guide to cat and kitten nutrition covers what to feed.
Vaccinations: when, and why they matter
In the UK, a kitten’s primary course is two injections, usually at 9 and 12 weeks, given three to four weeks apart. Core vaccines protect against feline panleukopenia (feline infectious enteritis), feline herpesvirus and feline calicivirus — the cat flu and enteritis viruses that can be fatal in young, unprotected kittens — with feline leukaemia (FeLV) commonly included. A kitten is only considered fully protected after the second injection, which is why timing matters so much for the leaving date below. Our complete guide to kitten vaccinations explains what each vaccine does, why the timing works the way it does, and what to expect.
Some kittens need a third injection at around 15 weeks, and every cat needs a booster a year later and then as advised by the vet. Your own vet will set the exact protocol for your kittens.
Microchipping and the law
Since 10 June 2024 it is a legal requirement in England for cats to be microchipped by 20 weeks of age. In practice, responsible breeders chip kittens before they leave, so the new owner receives a kitten that’s already chipped and registered. The planner’s leaving date assumes the kitten is fully vaccinated, microchipped and registered before going home.
When can kittens leave for their new homes?
The GCCF strongly recommends that no kitten goes to its new home before 13 weeks, with the full vaccination course completed at least seven days beforehand so immunity has developed. That’s why the planner defaults to 13 weeks for the earliest leave date — a week after the second jab. Staying with mum and littermates until then is also vital for socialisation and confidence.
This is the date kitten buyers most want to know, so being able to give a firm, honest answer early builds trust. Point new owners to our new kitten checklist to help them prepare, and if you’re fielding lots of messages, dealing with kitten enquiries helps you find the right homes.
Socialisation: the weeks that shape temperament
One of the most important reasons pedigree kittens stay until 13 weeks is not visible on any scan: it is socialisation. The key window in which a kitten learns that people, handling, household noises and everyday life are safe and normal runs roughly from two to seven weeks, and the weeks that follow consolidate it. A kitten that is gently handled every day, exposed to the ordinary sounds of a busy home, and given plenty of positive human contact during this period grows into a confident, friendly cat. This is work the breeder does, in the home, while the kittens are still with their mother and littermates — and it is a large part of what separates a well-raised pedigree kitten from one reared in isolation. The planner’s timeline keeps those weeks in view so the social side is never an afterthought.
Planning your diary around the dates
The real value of mapping the whole timeline is forward planning. Once you have the dates you can book time off around the birth and the busy early weeks, avoid scheduling holidays across weaning or the vaccination visits, and give waiting families a realistic collection date rather than a vague “around Christmas”. It also helps you plan the next mating sensibly rather than back-to-back, giving the queen proper time to recover. Working backwards from a date you would like kittens to be ready — a school holiday, perhaps, when a family has time to settle a new kitten — you can even judge roughly when a mating would need to happen.
For the bigger picture of running a litter from start to finish, see our complete guide to breeding Siamese cats. And if you’re planning a pairing, the Siamese colour predictor shows which kitten colours that mating can produce, with the genetics explained behind it.
Cat pregnancy and kitten timeline: FAQ
How long is a cat pregnant for?
About 65 days on average, with most queens delivering between 63 and 67 days after mating — a little over nine weeks.
How soon can you tell if a cat is pregnant?
A vet can usually confirm by palpation or ultrasound from around day 21 (three weeks). “Pinking-up” of the nipples can be visible at home from about two to three weeks.
When do kittens start weaning?
Weaning usually begins around four weeks of age and is generally complete by eight to ten weeks. See our weaning guide for the full process.
How many vaccinations does a kitten need?
A primary course of two injections, typically at 9 and 12 weeks in the UK, followed by an annual booster. Some kittens need a third injection at around 15 weeks — your vet will advise. Our kitten vaccinations guide has the detail.
What age can kittens leave their mother?
The GCCF recommends no earlier than 13 weeks, with the full vaccination course finished at least seven days before. This protects the kitten’s health and supports proper socialisation.
This guide is general information for planning, not veterinary advice. Always follow your own vet’s and the GCCF’s current guidance for your cats.
