The weight of a newborn kitten varies based on his breed and the number of littermates he has, according to the American Society for the Prevention of Cruelty to Animals. After birth, a healthy kitten should gain weight daily; if yours is not, you should take him to the vet.
Proper Weight Gain
A young kitten should gain approximately a quarter-ounce to a half-ounce each day until he reaches between 4 and 5 weeks old and is weaned onto solid foods. Within the first week, he should almost double his weight, according to the NYC Feral Cat Initiative. Kittens still eating from a bottle need approximately a quarter-ounce of formula per ounce of weight each day to stay well-fed and hydrated, according to the Kitten Rescue website. One that doesn't gain weight or loses weight is not thriving or eating properly and should be taken to a vet to check for health problems or physical deformities. Young kittens are fragile and won't survive long without proper nutrition.
First Few Months
Once he begins to eat solid foods, a typical 5-week-old kitten should weigh about 1 pound. Up until this point he will have gained approximately 3 ounces per week, according to the Feral Cat Coalition. For the next few weeks, he'll transition from formula or his mother's milk onto canned or dry kitten food. Mix the food with formula during this time, slowly decreasing the amount of formula in the food until he's eating only solid foods. With three to four small meals per day, your kitten should gain an average of 1 pound per month for his first 4 months of life, according to VetInfo.
Kittens need twice the caloric intake as full-grown cats, according to the Avalon Animal Hospital. Feed your little one food designed for kittens, which has a higher fat and protein content than other foods, until he reaches 1 year old. Follow the manufacturer's recommendations for the amount to feed him each day, typically around 200 calories each day for kittens weighing less than 5 pounds, according to the National Research Council of the National Academies. By the time the kitten reaches around 6 months of age, he should be approximately half the size of an adult cat. The average adult domestic cat weighs between 8 and 10 pounds, according to the Association for Pet Obesity Prevention. This means your little guy should weigh around 4 to 5 pounds at 6 months old.
Consult with your veterinarian and have her weigh your kitty during visits to ensure that your kitten is gaining weight when he is younger and at a healthy weight as an older kitten. A kitten that is too thin and malnourished can end up developing health issues that can affect his growth.
While kittens that are bottle-feeding should have round, full tummies, kittens older than 6 months old should look more like adults. You should be able to feel an older kitten's ribs just slightly through his skin. If not, check with your vet to ensure that your furry buddy isn't overweight.
Because weights vary between breeds -- with some breeds generally smaller, like the Siamese, and some larger, like the Maine Coon -- speak with your vet about your little guy's weight. She'll be able to tell you what the age-appropriate weight is for your particular little kitten.
- American Society for the Prevention of Cruelty to Animals: Newborn Kitten Care
- NYC Feral Cat Initiative: Bottle-Feeding & Care of Orphaned Kittens
- Association for Pet Obesity Prevention: Ideal Pet Weight Ranges
- National Resource Council of the National Academies: Your Cat's Nutritional Needs
- A Safe Haven for Cats: Caring for Newborns
- Kitten Rescue: Kitten Care Handbook
- Best Friends Animal Society: Feeding and Caring for Bottle Babies
- Feral Cat Coalition: Raising Orphan Kittens
- VetInfo: Weight Loss and Loss of Appetite in Cats
Based in Las Vegas, Susan Paretts has been writing since 1998. She writes about many subjects including pets, finances, crafts, food, home improvement, shopping and going green. Her articles, short stories and reviews have appeared on City National Bank's website and on The Noseprint. Paretts holds a Master of Professional Writing from the University of Southern California.