By 12 weeks the kitten is 2 of 2 to 3 shots in, sits at 1.2 to 1.6 kg, and needs three things in the room that are cheaper to install now than to fix later: something to scratch, something to climb, somewhere to hide. The monthly growth check from here runs at about 5 g a day, and that number is the last early warning you get for free.
Where 1.2 to 1.6 kg comes from
The checkpoints line up: 400 to 600 g at week 6, 700 to 900 g at week 8, 1.2 to 1.6 kg at week 12. That is a steady 100 to 150 g a week, and a kitten that has tracked the middle of each band is unremarkable in the best sense.
Weigh 3 mornings running on a 1 g scale before the first meal. A single reading at 1.25 kg tells you less than a trend. Between weeks 8 and 12 the spread between kittens widens from about 200 g to about 400 g, so compare the kitten to its own curve, not to a littermate that happened to be the biggest of the litter.
Two flat weeks mean something else at this age: with the baby teeth through and dry food on the menu, a stall points at parasites, dental pain, or a meal that quietly went missing.
Shots: 2 of 2 to 3 by week 16
The FVRCP course started at 8 weeks, so week 12 is the second dose, given 21 to 28 days after the first. The third, if the vet recommends one, lands at 16 weeks, and the course closes at 16 to 20 weeks. Two doses is the minimum for a kitten that started at 8 weeks; 3 is common when the start was early or the history is unknown.
Rabies sits at 12 to 16 weeks, legally required in most US states and best given in a separate visit 7 to 14 days away from the FVRCP so a reaction can be attributed. FeLV needs 2 doses 3 to 4 weeks apart, starting at 9 to 12 weeks, and is worth it for a cat that will meet other cats.
Keep the record in one place: dates, product names, weight on the day. Boarding and most shelters ask for it at the door.
| Item | Normal range | Recheck | What to do |
|---|---|---|---|
| Weight | 1.2-1.6 kg | 7 days | 3 mornings, 1 g scale, before food |
| FVRCP doses | 2 of 2-3 | 21-28 days | Third at 16 weeks, course ends 16-20 weeks |
| Rabies | Week 12-16 | 7-14 days apart | Separate visit from FVRCP |
| Monthly gain | 5 g a day, 150 g a month | 30 days | Log the first of each month |
| Environment | 3 items | 30 days | Scratch, climb, hide |
Three environment items, with sizes
Something to scratch. A post at least 60 cm tall and stable enough that it does not rock, sisal or cardboard, placed next to where the cat already stretches rather than in a corner nobody uses. Two surfaces in 2 rooms beats 1 tall post in 1 room, because a kitten scratches where it wakes up and where it enters.
Something to climb. A tower with 3 levels and the top platform at 100 cm or higher. Height is the point: a cat that can get its head above human eye level stops using the kitchen counter as a lookout. Check that the base is wider than the top platform, or a 1.5 kg kitten at speed tips it.
Somewhere to hide. One covered bed or box with a 15 cm opening, plus 2 litter trays for 1 kitten, 3 for 2 kittens. Trays go at least 1 m apart, away from food and water, and scooped twice a day.
The monthly 5 g check
From week 12 the steep part of the curve is over. Growth slows to roughly 5 g a day, which is about 150 g a month, and that is the number to write down on the first of each month rather than a weekly figure. A kitten at 1.4 kg that is 1.45 kg a month later is doing exactly what it should.
Two months under 100 g of gain is the point to book a visit, not one slow month. Bring the log: a curve that has been flat since week 14 reads differently from one that dropped in the last 3 weeks, and the vet will ask exactly that question.
Feeding 1.2 to 1.6 kg
Three meals a day, 200 to 260 kcal, which is 170 to 220 g of wet food or 55 to 70 g of dry. Kitten food, not adult food, until 10 to 12 months: the calcium and protein density matters while the skeleton is still closing. Fresh water in 2 places, changed daily, in a wide shallow bowl.
Treats stay under 10 percent of the calories, so under 20 to 26 kcal a day. That is 4 to 6 small pieces, and it is also the entire training budget for carrier work and nail trims.
The 12-week vet visit
Fifteen minutes, 4 checks: weight on the same scale, teeth and gums, heart and lungs, and a body condition score. Ask for the score as a number out of 9 and write it next to the weight. At 12 weeks a score of 4 to 5 is right; a 6 in a kitten is a habit being set, not puppy fat to grow out of.
Settle the deworming schedule for the next 6 months here, and ask about a microchip, which most vets place from 8 weeks.
Play, sleep and the daily shape
Four play sessions of 5 to 10 minutes, spread across the day, ending with food or a chew. Kittens at this age sleep 18 to 20 hours, so 4 sessions fit around 4 wake windows. A kitten that bites hands at 21:00 has usually had 1 session too few and 2 hours too much idle time.
Call the vet for
- Weight under 1.2 kg at week 12, or 2 months with gain under 100 g
- Limping, or a leg the kitten will not put down
- Diarrhea past 24 hours, or vomiting 3 times in a day
- Breathing with the mouth open, or a resting rate over 40 a minute
- A swollen belly with a visible spine, which means worms rather than fat
The 12-week checklist
- Weigh 3 mornings and confirm 1.2 to 1.6 kg.
- Confirm dose 2 went in 21 to 28 days after dose 1, and book the 16-week date.
- Put the scratch post where the cat already stretches, not in a spare room.
- Get the tower to 3 levels with the top at 100 cm and check it does not rock.
- Set 2 trays 1 m apart and a covered bed with a 15 cm opening.
- Write the monthly weight date on the calendar for the first of each month.
Week 12 is the handover from survive to live: 1.2 to 1.6 kg, 2 of 2 to 3 shots, 3 environment items, and a 5 g a day check that runs for the next 6 months. The earlier checkpoints are in the week-by-week milestones, the handling work continues in the socialization checklist, and if a second cat is on the table the breed quiz is a reasonable place to start.
Terms mentioned in this article
Frequently asked
My kitten is 1.05 kg at 12 weeks. Should I be worried?
It is below the 1.2 to 1.6 kg band, so check the trend before the number. If the kitten was 900 g at week 8 and is 1.05 kg now, it gained 150 g a week and is simply small. If it was 950 g at week 8, it gained 100 g in 4 weeks, which calls for a stool sample, a body condition score and a look at how many meals it actually eats.
Does a 12-week kitten need the third FVRCP shot?
Two doses are the minimum when the course started at 8 weeks and the second landed 21 to 28 days later. A third at 16 weeks is common when the kitten started early, came from a shelter, or has an unknown history, because maternal antibodies may have blocked the first dose. The course should close at 16 to 20 weeks either way.
How fast should growth go after 12 weeks?
About 5 g a day, or 150 g a month, which is much slower than the 100 to 150 g a week of the week 6 to 12 stretch. Weigh on the first of each month rather than weekly. One slow month is normal; two months with under 100 g of gain is the point to book a visit with the log in hand.