How To Tell How Old a Cat Is

If you’re one of the many pet parents who adopted an older cat, you may wonder how to tell how old a cat is. A few key factors can give you a reasonably accurate idea of your cat’s age.

Cat Life Stages

A cat’s lifespan can be divided into four stages: kitten, young adult, mature adult, and senior. 

Kitten (Under 1 Year Old)

Cats under 1 year old are classified as kittens. Kittens are growing, so their body size will increase throughout this time, and they will progressively lose their baby teeth and gain their adult teeth.

Young Adult (1–5 Years Old)

Young adult cats have reached their final adult body size and will generally have clear eyes, a smooth coat, plenty of energy, and fluid body movements. Toward the end of this life stage, some cats might start to develop plaque and tartar on their teeth. 

Mature Adult (6–10 Years Old)

Mature adult cats might begin to develop cloudy eyes, slightly stiff body movements as arthritis begins to develop, and more plaque and tartar on their teeth. They might also decrease grooming behaviors, resulting in a slightly less smooth coat and potentially higher risk for matting.

Senior (Over 10 Years Old)

Senior cats can show their age in a number of ways, including: 

• Increased cloudiness in their eyes

• Loss of lean muscle mass

• Less elastic skin

• Rougher and more matted coat as grooming further decreases

• Even greater teeth issues, such as bone loss, along with plaque and tartar

• Stiffer body movements as arthritis becomes more pronounced

How To Tell a Cat’s Age

So, how can you tell how old your cat is? There are a few physical and behavioral factors to look at. 

Teeth

A kitten’s front teeth on the top and bottom (the incisors) are generally smaller and pointier than an adult cat’s teeth. 

For the most part, young adult cats will have 26 teeth that are free of plaque, tartar, and gum inflammation. Mature adult and senior cats can start to develop more pronounced signs of gum disease and other dental issues as they age. 

Coat

Kittens and young adult cats generally do an excellent job of maintenance grooming, and their coat is soft, smooth, and free of mats. 

Mature adult and senior cats sometimes decrease their grooming activities, resulting in a rougher coat that might mat more easily. Older felines can also lose some of the elasticity in their skin, resulting in their skin feeling thinner and more dehydrated when you pet them. 

Eyes

Kittens and young adult cats generally have eyes that are bright, clear, and free of discharge. 

Mature adult cats might start to show some cloudiness in the interior chambers of their eyes, called nuclear sclerosis. Nuclear sclerosis is a normal aging change in cats and may become more pronounced in senior cats. 

Senior cats can also develop cataracts, a thickening and increased cloudiness in the lens of the eye.

Body Condition

Kittens gain weight and lean muscle mass as they grow into young adult cats. Young adult cats will often have the highest percentage of lean muscle mass of any age group and the most appropriate body condition score, as their fat stores are often the most balanced given their higher metabolism and activity level along with a generally good appetite. 

Mature adult cats sometimes see an increase in body weight as their metabolism starts to slow down. They can also begin to show some degree of lean muscle mass loss as they approach the higher end of their age bracket. 

Senior cats are at the greatest risk of losing body weight as lean muscle mass decreases at the fastest rate compared to the other life stages. 

Movement

Kittens and young adult cats usually walk and run with easy, fluid movements and can jump up and down off elevated spaces without much difficulty. 

Mature adult and senior cats often develop arthritis, which makes them walk with a slower, stiffer gait and makes them less willing to jump. Cats with arthritis pain might walk with their back and neck arched; severe arthritis in one limb can even cause noticeable limping. 

Energy Level

All cats sleep a lot, but kittens and young adult cats usually spend less time sleeping during the day than mature and senior cats. Younger cats are overall more energetic and spend more time playing and roaming around the home than older cats.

A quick note: The information presented here is simply a guideline. Cats of any age can vary in the overall condition of their teeth, eyes, coat, lean muscle mass, mobility, and energy level, depending on health issues and preventative care at home. 

Why Is It Important To Know Your Cat’s Age?

Knowing your cat’s age helps you give your pet the best care. It allows you to understand what health conditions your pet is susceptible to, so you can discuss risk factors with your veterinarian and start any recommended preventative care.

For example, healthy young adult cats might need to see their veterinarian only once a year for general exams, vaccines, and flea and tick prevention. 

Mature adult cats, depending on their overall health, might need to be seen every six to 12 months for blood work as well as general preventative care. They might need professional dental cleanings and mouth X-rays yearly to monitor their teeth and gums. 

It’s typically recommended that senior cats see their primary care veterinarian every 6 months for blood work, tooth and gum monitoring, and an exam to monitor the condition of the kidneys and other major organs.