Kitten Weight Chart: Average Weight by Age and Growth Milestones

By Tailwisp Editorial TeamUpdated October 20, 20264 min read

Weighing a kitten is one of the best ways to track health. A steady climb on the scale means the kitten is eating, absorbing food and growing. A flat line or a drop can be the first sign of trouble. This chart shows the usual pattern, and how to use it.

Average weights by age

These are rough averages for domestic cats. Individual kittens vary widely.

Large breeds such as Maine Coons, Ragdolls and Norwegian Forest Cats grow longer, and become much heavier. See maine coon and ragdoll. Small breeds such as Singapuras are lighter.

A simple rule

In the first weeks, a healthy kitten gains about half an ounce to an ounce per day, or about 4 to 8 ounces per week. A kitten should double its birth weight in the first week, and triple it by three weeks. After the first few months, gains slow.

How to weigh your kitten

Use a digital kitchen scale that measures in grams or ounces. Place a small box or towel on it, zero the scale, then place the kitten. Weigh at the same time each week, before a meal. Record the number. For older kittens, you can weigh yourself holding the kitten, then subtract your weight.

Factors that affect weight

• Breed. Large breeds grow slowly and for longer. See kitten growth and development week by week.
• Sex. Males are often larger than females.
• Litter size. Kittens in large litters may be smaller.
• Nutrition. Quality and quantity of food. See kitten feeding amounts by age.
• Parasites and illness. Worms and infections slow growth. See kitten deworming guide.
• Genetics.
• Neutering, which can lead to extra weight gain if food is not adjusted. See feeding a neutered or spayed cat.

Signs of slow growth

• Weight gain that stalls or falls.
• A weight well under the range for several weeks.
• Poor appetite, lethargy or cold body.
• A very thin body and prominent ribs.
• A dull coat.
• A pot belly with a thin frame, suggesting worms.

Call your vet. See kitten not eating.

Signs of overweight

• No waist, and ribs hard to feel.
• Rapid weight gain beyond the chart.
• A sagging belly.

Reduce treats, and measure meals. See how much should i feed my cat.

Aging a kitten by weight

Weight alone is a poor guide to age, but can help combined with teeth and eyes. See how to tell a kitten's age.

Fading kitten syndrome

Newborn kittens that are small, weak or stop gaining may be fading. This is an emergency. Warm the kitten gently, and call a vet. See how to bottle feed a kitten.

Growth stages

• 0 to 2 weeks: eyes closed, entirely dependent on mother.
• 2 to 4 weeks: eyes open, begin to walk.
• 4 to 8 weeks: weaning, play, socialization.
• 2 to 6 months: rapid growth, teething, energy.
• 6 to 12 months: adolescence, growth slows.

Tracking tips

Keep a notebook, or use a spreadsheet. Take photos each week. Share with your vet at each visit.

Using the chart sensibly

Do not worry if your kitten sits a little above or below the numbers. Look at the trend, the body shape and behavior. A kitten that is lively, eats well and gains steadily is usually fine even when smaller than a sibling. If you adopted a kitten without knowing its age, use the weight, teeth and eyes together, and ask your vet for an estimate.

Growth spurts and plateaus

Kittens grow in spurts, and weight may plateau for a few days before jumping. Weigh weekly rather than daily, to avoid false alarm. If weight is flat for two weeks, or drops, call your vet.

Weighing multiple kittens

In a litter, weigh each kitten at the same time of day, mark them with a safe colored collar or dot of nontoxic dye, and chart each separately. Compare each against its own progress, not just against littermates. A kitten that falls behind may need supplemental feeding or a vet check. Keeping a clear record helps rescuers and foster carers make quick decisions about care.

When to see a vet

See a vet if your kitten is not gaining as expected. Use the US vet directory to find a clinic.