Maine Coon Weight by Age: The Complete Growth Chart

The first time I weighed my Maine Coon properly, I laughed at myself. I had spent weeks guessing from photos and lifting him like a bag of shopping, and the real number on the scale told a much calmer story.

That is why I keep this chart close and check it with my hands, not just my eyes. The numbers below are typical ranges from owners and breed sources I trust, and they are guides, not grades for your cat.

How to Read This Chart

Maine Coons grow slowly and keep maturing for three to five years, so a young cat can look unfinished for a long time. I cover that slower story in full in my Maine Coon growth guide, and adult length and height in depth in my Maine Coon size guide. This page stays focused on one thing only, which is what the scale should roughly say at each age.

Males usually run heavier than females from about three months onward, and the gap tends to widen with age. Two kittens from the same litter can still sit pounds apart and both be perfectly healthy.

The video above gives a useful visual sense of full grown size and weight. I still come back to the table and the hands on check, because a video cannot tell you how your own cat feels under that thick coat.

The Weight Chart

Use this table for Maine Coon weight by age as a starting point, in pounds and kilograms. If your cat sits just outside a row, look at the trend over several weeks before you worry.

Age	Male	Female
Newborn	0.2 to 0.3 lb (0.09 to 0.14 kg)	0.2 to 0.3 lb (0.09 to 0.14 kg)
1 month	1.5 to 2.2 lb (0.7 to 1.0 kg)	1.3 to 2.0 lb (0.6 to 0.9 kg)
2 months	2.5 to 3.5 lb (1.1 to 1.6 kg)	2.2 to 3.2 lb (1.0 to 1.5 kg)
3 months	4.5 to 6 lb (2.0 to 2.7 kg)	4 to 5.5 lb (1.8 to 2.5 kg)
4 months	5.5 to 8 lb (2.5 to 3.6 kg)	5 to 7 lb (2.3 to 3.2 kg)
5 months	7 to 10 lb (3.2 to 4.5 kg)	6 to 8.5 lb (2.7 to 3.9 kg)
6 months	9 to 12 lb (4.1 to 5.4 kg)	8.5 to 11 lb (3.9 to 5.0 kg)
9 months	10 to 15 lb (4.5 to 6.8 kg)	9 to 13 lb (4.1 to 5.9 kg)
12 months	12 to 17 lb (5.4 to 7.7 kg)	11 to 15 lb (5.0 to 6.8 kg)
18 months	13 to 20 lb (5.9 to 9.1 kg)	10 to 16 lb (4.5 to 7.3 kg)
2 years	13 to 22 lb (5.9 to 10.0 kg)	9 to 17 lb (4.1 to 7.7 kg)
Adult, 3 to 5 years	13 to 25 lb (5.9 to 11.3 kg)	8 to 18 lb (3.6 to 8.2 kg)

Kitten weight climbs fastest in the first six months, when good food and sleep do most of the work. Gains often come in bursts, with a big week followed by a quieter week that still ends in the right direction.

After the first birthday, the weekly changes get smaller and harder to notice. Most of the later gain is chest, shoulder, and muscle rather than height, which is why photos can look unchanged while the scale creeps up.

What Moves the Number

Family lines matter more than any chart, because big parents tend to have big kittens. If you know what the mother and father weigh, you already have the best clue about your own cat.

Food matters too, especially in kittenhood when protein builds frame and muscle. My guide to the best food for Maine Coons covers the options I compare when I shop, but measured portions matter as much as the brand.

Neutering and spaying do not set final size, though they can make weight gain easier afterwards. I watch portions a little closer in the months after the procedure and keep play daily.

How to Weigh at Home

You do not need a vet scale on your kitchen floor to get a useful number. You need the same method, the same time of day, and a note on your phone.

The Bathroom Scale Method

Step on the scale holding your cat and write that number down. Step on again without the cat, then subtract your weight from the first number to get the cat weight.

It is not perfect to the last ounce, but it is honest and repeatable for adult cats. Do it once a month, before breakfast if you can, and the trend will be clear enough to act on.

The Kitchen Scale for Kittens

For kittens under about 5 lb, a flat kitchen scale works far better. Put a shallow box or tray on the scale, zero it out, then set the kitten inside for a few calm seconds.

Weigh young kittens at the same time each week and look for steady gain, not a perfect daily line. A kitten who gains most weeks and eats, plays, and uses the litter tray normally is usually doing well.

Keeping a Simple Log

I keep three columns only, which are date, weight, and one short note about appetite or energy. Anything fancier and I stop doing it, and a simple log I actually keep beats a perfect chart I abandon.

Bring that log to vet visits, because it turns a vague worry into a clear picture. Vets can spot a slow drift in seconds when the numbers are written down in order.

Body Condition Check

The scale tells you weight, but your hands tell you condition, and body condition matters more than the number on the scale. The AVMA guide to your pet healthy weight explains the same idea, which is learning to recognise underweight, ideal, and overweight condition by feel and shape.

Do this check once a month when your cat is relaxed and standing. Thick fur hides a lot on a Maine Coon, so trust your fingers more than the outline you see from across the room.

Ribs

Run both hands lightly along the sides, as if you are stroking the coat. At a healthy weight you should feel the ribs easily under a thin layer of cover, without pressing hard and without sharp edges.

If you have to push to find the ribs, there is likely extra fat building up. If the ribs feel stark with almost nothing over them, your cat may be underweight or losing muscle.

Waist

Look down from above while your cat stands or walks away from you. A healthy cat has a gentle inward curve behind the ribs, even under a heavy coat.

From the side, the belly should tuck up a little toward the back legs. A straight line from above or a belly that hangs and swings can point to extra weight, though a loose primordial pouch alone is normal for many cats.

Belly and Back

Feel along the back and hips with flat fingers, not fingertips. The spine and hip bones should be smooth to find, not hidden under padding and not jutting out.

The Cornell Feline Health Center notes similar risks in its guide to care of obese cats, where extra weight is linked to diabetes and joint trouble. That is why a monthly hands on check is worth the two minutes it takes.

Signs Your Cat Is Underweight

Ribs, spine, or hip bones that show through the coat are the clearest warning sign. You may also notice a narrow waist that looks pinched rather than gently curved.

Low energy, a dull coat, and leaving food that used to vanish quickly can sit alongside the weight change. In kittens, the warning is simpler, which is a week with no gain when gain should still be steady.

Do not just add extra meals and hope if you see these signs for more than a few days. Parasites, dental pain, thyroid trouble, and other illness can all sit behind poor condition, and only an exam can sort them out.

Signs Your Cat Is Overweight

The first sign I notice is usually the ribs getting harder to feel. The second is less jumping, shorter play sessions, and more effort reaching around to groom the back and hindquarters.

A rounder face, a thicker neck, and a belly that stays low from the side can also build up so slowly that you miss them day to day. Monthly weighing catches what daily looking misses, which is exactly why I do both.

Extra weight is not a cosmetic issue on a large frame like this. It adds strain to joints and raises the risk of diabetes and liver trouble, so a gentle, vet guided plan is always better than a sudden crash diet.

When a Change Means a Vet Visit

Book a visit if your cat loses or gains a lot in a short time without a clear reason you can explain. As a rough home rule, a change of about 5 percent of body weight in a month deserves a call, and faster change deserves one sooner.

Go sooner if weight change comes with vomiting, diarrhoea, thirst changes, hiding, or a clear drop in appetite. Kittens, seniors, and cats with known health conditions should not wait for the next routine visit when the trend turns.

I am an owner, not a vet, and I do not try to diagnose from a scale at home. What I can do well is notice early, bring a clear log, and let the vet do the medical part properly.

Myths I Hear a Lot

The biggest myth is that every Maine Coon should pass 20 lb to count as real. Plenty of healthy females and smaller framed males will never get near that number, and chasing it with extra food only creates a fat cat, not a bigger one.

Another myth is that a heavy coat means a heavy cat, or the reverse in summer. Fur adds drama, not pounds, which is why the rib check matters more than any photo on social media.

The last myth is that slow growth means something is wrong by default. Slow is normal for this breed, as long as the direction is steady, the condition feels right, and your vet is happy at routine checks.

If you take one habit from this page, make it a monthly weigh in plus a monthly rib check. Together they tell you more than either one alone, and they take less time than making tea.

Frequently Asked Questions

How much should a Maine Coon weigh at 6 months?

Most Maine Coons weigh about 8.5 to 12 lb at six months, with males usually near the top of that range. Females often sit a little lower, and a healthy kitten outside the range is not automatically a problem. Check body condition and steady gain alongside the number.

What is a healthy adult Maine Coon weight?

Healthy adult females usually weigh 8 to 18 lb and adult males usually weigh 13 to 25 lb. The wide range reflects frame size, muscle, and family lines rather than a single ideal number. A lean, active cat inside that range is in a good place.

How often should I weigh my Maine Coon?

Weigh kittens every week or two in the first six months, when changes happen fast. After that, a monthly weigh in is enough for most healthy cats. Weigh at the same time of day and write the result down so trends are easy to spot.

Why is my Maine Coon gaining weight but not growing longer?

After the first year, many Maine Coons fill out through the chest and shoulders instead of adding much length. Some of that filling out is normal muscle, but soft gain around the belly can also mean extra calories. Run a body condition check and adjust portions if the ribs are getting hard to feel.

When should weight loss in a Maine Coon worry me?

Unexplained loss, a sudden drop, or loss paired with low appetite or low energy should prompt a vet visit. Kittens who stop gaining for more than a week also need a prompt check. I never wait and watch with weight loss in a young or senior cat.