British Shorthair, American Shorthair, Siamese
Reference band (Medium (adult 9–13 lb)) Actual curve Alert point
Reference ranges come from breeding practice and veterinary guidance and are not a diagnosis. Individual variation, litter size and the queen's milk supply all cause normal fluctuation — see a vet if something looks wrong.
Why weight is the most important daily number
A newborn kitten cannot tell you anything and shows no useful early symptoms: it does not cry differently because it is dehydrated, and it does not look worse because it is too weak to suckle. Weight is the only quantified measure that gives you a day or two of warning. By the time a kitten visibly looks wrong, the window in which it was easily saved has usually closed. That is why the routine is weighing every kitten at a fixed time each day and writing it down, rather than judging by feel.
How to read the reference band
The gold area is the usual range for kittens of that adult size class — roughly 90–120 g (3–4 oz) at birth, up to 140 g for large breeds, then 10–15 g a day, doubling by one week. But the band is background, not a pass mark: kittens from a litter of six are naturally smaller than a litter of two, and an entire litter can track along the lower bound in perfect health. Put your attention on the direction of your own curve — it has to keep going up.
Three red lines — act on any one of them
First, weight falling on two consecutive recorded days: one fall can be scale error or a recent bowel movement, two is a trend. Second, a single drop of 8% or more, which usually means dehydration or acute diarrhoea. Third, dropping back below birth weight — one of the most dangerous signs in a newborn, typically insufficient milk, a cleft palate, or a kitten too weak to suckle. These three are identical to the weight-guard rules inside the Cattery Manager app; this page does not invent its own standard.
Frequently asked questions
How much weight should a kitten gain per day?
A newborn typically gains 10–15 g (about 0.35–0.5 oz) a day, and large breeds can manage 15–25 g. By one week old the kitten is usually double its birth weight. But the number to watch is the trend rather than any single day: as long as it climbs every day, slow is usually fine, whereas two consecutive days without gain — or any loss — needs intervention immediately, even if the absolute weight still sits inside the normal range.
What do I do if a kitten stops gaining or starts losing?
Check three things first: the incubator temperature (86–90°F / 30–32°C in the first week — a cold kitten stops suckling and cannot digest), the queen’s milk supply, and whether this kitten is being pushed off the teat by littermates. Then start supplementing with kitten milk replacer every 2–3 hours, logging the amount each time. If there is no recovery within 12–24 hours, or the kitten has fallen below birth weight, see a vet the same day to rule out a cleft palate, infection or neonatal isoerythrolysis.
Why is "below birth weight" the alert line instead of "below the reference band"?
Because the band cannot cover individual and breed variation: a small queen with a litter of six may produce kittens that all sit naturally under the medium-breed lower bound while being perfectly healthy. The reliable danger signal is the kitten’s own trend turning over — two consecutive falls, a single drop of 8% or more, or a return below birth weight. Those three rules drive the red alerts here, and they match the weight guard inside the Cattery Manager app exactly.
How often should I weigh, and how do I get an accurate reading?
Daily at a fixed time during the first week — ideally the same moment before a feed. Every other day for weeks two to four, then weekly. Use a digital kitchen scale accurate to 1 g (0.1 oz), put a small container on it and tare. What matters is consistency: a kitten can differ by tens of grams before and after a feed, so comparisons only mean something when every weighing happens in the same state.
Can I switch between grams and ounces?
Yes — use the toggle above the chart, and everything including the reference band, the table and the alerts re-renders in that unit. Weights are always stored in grams internally, so switching units never changes a stored value or moves an alert threshold. Enter numbers in whichever unit your scale reads.