How cat years convert to human years
The commonly used conversion gives the first year about 15 human years and the second year another 9, so a two-year-old cat is roughly 24 in human terms. After that, each cat year adds about four human years.
This is an approximation, not a biological measurement. Breed, lifestyle and healthcare shift the real picture, but the stages line up well with when cats typically need different kinds of care.
Life stages and what changes
Kittens need vaccines, parasite prevention and lots of play. Junior cats from one to two years are still growing socially and physically. Adults from three to six are usually at their healthiest. Mature cats from seven to ten benefit from annual bloodwork, and seniors from 11 onward need closer monitoring for kidney disease, thyroid problems, arthritis and dental disease.
Indoor cats often live into their late teens. Outdoor access increases the risk of trauma and infectious disease, which can shorten that lifespan considerably.
Keeping an older cat comfortable
Cats hide discomfort well. From around age seven, watch for weight loss, changes in thirst or urination, reduced jumping, and grooming changes. Simple adjustments help: low-sided litter boxes, ramps or steps to favourite spots, softer bedding and food that is easier to chew.