Kitten Weight Chart by Week

How to use this kitten weight chart

1. Enter the age. Use days for a newborn, weeks up to about two months, and months after that. The chart switches to the day-level data automatically for anything under eight weeks, because at that age a single day makes a real difference.
2. Enter the weight. Grams are the default and the most useful unit for a young kitten — a healthy newborn gains 7 to 15 grams a day, which is invisible on a scale that reads in ounces. Switch to ounces, pounds, or kilos any time; the whole chart follows.
3. Set the breed size and sex if you know them. A Maine Coon and a Siamese are not on the same curve past about two months, and males pull to the top of the band once they hit puberty. Both refinements fade in gradually rather than jumping, because that's how growth actually works.
4. Log every weigh-in. This is the part that matters. One weight tells you where a kitten sits; two tell you which way it's going. Add each weigh-in and the tool plots the trajectory and grades the daily gain against the veterinary standard.
5. Print the log. The PDF gives you the weigh-ins so far plus a blank tracking sheet with the healthy range for each upcoming day already filled in — stick it on the fridge or hand it to a foster.

Why this kitten growth chart is different

Search "kitten weight chart" or "kitten growth chart" and you get a wall of static images: a PDF from a shelter, a JPEG on a pet blog, a printable someone is selling on Etsy. They all answer the easy question — what should a kitten weigh? — and none of them answer the one people actually type it for, which is is mine okay?

• It covers the whole first year in one place. The best neonatal chart in existence stops at eight weeks. The best growth charts start at eight weeks. This one joins them into a single continuous curve from birth to twelve months, so you never have to switch references mid-kitten.
• The first eight weeks are day by day. Not "1–2 weeks: 150–350 g" but day 11, day 12, day 13 — because a fostered neonate is weighed daily and a week-wide band hides exactly the problem you're weighing for.
• It grades the trend, not just the number. Log two weigh-ins and the chart tells you the grams gained per day and whether that's normal, slow, or a reason to call a vet today. A small kitten gaining well is usually fine; an average-sized kitten that has stopped gaining is not. No static chart can tell those apart.
• It's honest about breed and sex. Most charts either ignore breed entirely or silently multiply everything. This one shows you the standard curve, then eases a breed-size and sex adjustment in over the weeks when those differences genuinely emerge.
• The printable is free and pre-filled. A branded weight log with the healthy range for every upcoming day already written in — the thing people are currently paying for on Etsy — plus a share link and a free embeddable widget for rescues and foster networks.
• It shows its work. Every number is sourced below, and an automated test re-derives all fifty-six cells of the source chart on every single site build, so the math can't quietly drift. Reviewed by a board-certified feline veterinarian.

How the weight ranges are calculated

The chart is built from two published sources, joined so the curve is continuous where they meet.

Birth to eight weeks comes from the ASPCApro Kitten Age & Weight Chart, the reference shelters and foster programmes use to age and monitor kittens. That chart turns out not to be a hand-built table at all: every one of its fifty-six printed cells falls out of a single rule — a kitten starts at about 100 grams and gains between 7 and 15 grams a day. So the low line is 100 + 7 × (days − 1), the high line is 100 + 15 × (days − 1), and the midpoint sits exactly between them. Day one is the printed birth row, 70 to 115 grams. The midpoint reaches 705 grams at eight weeks, which is the classic 1.5 lb adoption weight — the three lines agree with each other because they come from one rule.

Eight weeks to twelve months interpolates between published growth anchors, starting from exactly where the ASPCA chart leaves off so there's no step at the seam. Those anchors follow the familiar rule of roughly a pound a month, decelerating after six months, and are cross-checked against the WALTHAM Kitten Growth Charts, the Royal Canin kitten percentile chart, and PetMD's development stages. At twelve months the typical line lands at 9 lb, just under the 8–12 lb adult range for a domestic shorthair — which is right, because a cat at its first birthday is about 95% grown and still filling out.

Breed size is applied from eight weeks and reaches full effect by six months (0.82× for fine-boned breeds, 1.22× for large frames, 1.45× for giants). Sex is applied from sixteen weeks and reaches full effect by six months, narrowing the band the same way our average and ideal cat weight checker does for adults, so the two tools never contradict each other. Both fade in rather than switching on, because breed size and the difference between males and females emerge during growth, not at birth.

Daily gain is judged against the ASPCA's own footnote — normal kittens gain 7 to 15 grams a day — for anything under eight weeks. Past that, the rule no longer applies, so the tool compares your kitten's gain to the slope of its own curve over the same interval instead. Any weight loss is flagged at any age; under four weeks it's flagged as urgent.

Kitten weight by week: three worked examples

The two-week-old bottle baby

A fostered kitten at fourteen days should weigh 191 to 295 grams. If it was 150 g a week ago and it's 220 g today, that's 10 grams a day — squarely inside the healthy 7–15 g range, and the single most reassuring number you can get at this age. If it were 178 g, that's 4 g a day: still gaining, but too slowly, which means more frequent feeds, checking the kitten is warm enough to digest, and a vet call. See our kitten feeding schedule calculator for the formula amount that goes with this weight.

The eight-week-old you're about to adopt

Eight weeks is the seam in the chart and the standard adoption age. The healthy range is 485 to 925 grams (about 1.1 to 2 lb), typically around 705 g. A kitten at the bottom of that band isn't necessarily unwell — shelter and stray kittens often run light and catch up fast — but it is the age to switch from a growth formula to measured meals of a proper kitten food. Dr. Anand's shortlist is in the best kitten food guide.

The six-month-old that looks huge

At six months a standard-frame kitten sits in the 2,177 to 3,402 gram band (roughly 4.8 to 7.5 lb). Set the breed size to giant and the same age reads 3,157 to 4,933 g — a Maine Coon at five months can outweigh an adult Siamese and be perfectly normal. Kittens are never labelled overweight here for that reason; above the band just means ahead of the curve. What matters is that meals stay measured rather than free-fed, so the growth spurt turns into a lean adult. When the first birthday comes, move over to how much to feed a cat by weight.

Frequently asked questions

How much should a kitten weigh by age?

As a rough guide: about 100 g at birth, 150–250 g at one week, 250–350 g at two weeks, 485–925 g at eight weeks, then roughly a pound a month — around 3 lb at three months, 4 lb at four months, 6 lb at six months, and 8 to 11 lb at twelve months for a standard-frame cat. Small breeds finish lighter and giants keep growing to three to five years. Enter your kitten's exact age above for its specific band rather than working off the nearest month.

How much weight should a newborn kitten gain per day?

Seven to fifteen grams a day, per the ASPCA chart this tool is built on; Kitten Lady puts it at 7 to 14. That's why grams matter so much in the first few weeks — a whole day's healthy gain is less than half an ounce. A neonatal kitten that isn't gaining, or that loses weight on any day, needs a veterinarian the same day. Weigh at the same time each day, before a feed, and write it down.

Is my kitten underweight?

If its weight is below the bottom of the band for its age, it's small for its age — and if it's more than a quarter below, that's worth a vet visit this week. But a single reading is weak evidence. The runt of a litter can sit under the band for weeks and be completely healthy as long as it's gaining steadily, while a kitten in the middle of the band that has stopped gaining is the one in trouble. Log two weigh-ins above and the tool will tell you which of those you have.

When do kittens stop growing?

Most cats reach close to their adult size at around twelve months and finish filling out by eighteen months. Large and giant breeds — Maine Coons, Ragdolls, Norwegian Forest cats, Savannahs, Siberians — take much longer and are commonly still gaining at three to five years old. Switch from kitten food to adult food around the first birthday for a standard cat, or nearer eighteen months for a giant breed.

What's the difference between a kitten weight chart and a kitten growth chart?

In practice, nothing — people use both phrases for the same thing, and this page covers both. A weight chart usually means the table of healthy ranges by age; a growth chart usually means plotting your own kitten's weights over time against those ranges, the way a paediatric growth chart works. This tool does both: the chart above is the reference, and the growth log plots your kitten on it.

Related tools

• Kitten Feeding Schedule Calculator — how much and how often to feed at your kitten's exact age →
• Cat Weight Chart by Age & Breed — the adult side of the same question, breed by breed →
• Average & Ideal Cat Weight Checker — is your grown cat underweight, ideal, overweight, or obese? →
• Cat Diet & Weight-Management Calculator — daily calories and exact portions once your kitten is grown →
• Browse all free cat-care tools by Dr. Anand →

What a growing kitten needs

The chart suggests gear that fits your kitten's stage and result: a gram-accurate scale and milk replacer for a neonate, a bigger pet scale and calorie-dense kitten food for one that needs to catch up, and measured feeding for one that's racing ahead. A scale is the one non-negotiable — you cannot use a growth chart without one, and the cheap gram scales sold for whelping are perfectly good. For the full shortlists, see Dr. Anand's guides to the best kitten food, best wet cat food, and best dry cat food, plus a water fountain to build good hydration habits early.

Methodology & sources

Birth to eight weeks reproduces the ASPCApro "Kitten Age & Weight Chart" (2023) cell for cell: low = 100 + 7 × (days − 1) grams, high = 100 + 15 × (days − 1), with day one as the printed 70–115 g birth row, matching that chart's stated basis that "normal kittens gain 7-15g/day." Kitten Lady's weighing guidance (approximately 7–14 g per day; 150–250 g at one week, 250–350 g at two weeks, 650–750 g at six weeks) sits inside the same band. Eight to fifty-two weeks interpolates linearly in grams between published anchors seeded from the ASPCA week-eight endpoint, following the pound-a-month rule decelerating after six months, cross-referenced against the WALTHAM Kitten Growth Charts, the Royal Canin kitten percentile growth chart, Pawlicy Advisor's cat weight chart, and PetMD's kitten development stages. Breed-size multipliers (0.82 / 1.00 / 1.22 / 1.45) ramp in from week 8 to week 26; the sex split (female to the lower 65% of the band, male to the upper 65%) ramps in from week 16 to week 26 and is the same model used by our adult weight tools. Adult projection holds the kitten's position in the band constant to week 52 and applies a maturity factor of 1.05, or 1.25 for large and giant breeds, per Royal Canin's guidance that a kitten reaches 80% of adult weight by eight months and adulthood at twelve to fifteen months. Kittens are never classified as obese. The engine is validated by an automated fixture test — all fifty-six ASPCA cells, seam continuity, monotonicity across every breed and sex combination, classification boundaries, daily-gain verdicts, unit conversions, and agreement with our adult weight chart — that runs on every site build.

• ASPCApro — Kitten Age & Weight Chart (2023)
• Kitten Lady — Weighing Kittens
• WALTHAM Petcare Science Institute — Kitten Growth Charts
• PetMD — Kitten Development Stages and Kitten Age Chart
• Royal Canin — Kitten development from birth to adulthood; Pawlicy Advisor — cat weight chart by age and breed.

Reviewed annually for citation currency. About Dr. Anand · Last reviewed August 10, 2026.

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  Kitten weight chart by
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  &middot; Reviewed by Dr. Priya Anand, DVM, ABVP (Feline)
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