Cat years are the age of a cat in comparison to a human. Cats age at a different rate than humans, with shorter total life spans. When a cat is 1 in cat years, they are 15 years old in human years.
The average lifespan of a cat is 12-15 years, with some cats living up to 21 years. When thinking about cat years, consider the fact that once a cat is 15 years old in cat years, it is approximately 76 years old in human years. How long they live is based on their health, lifestyle and whether they are indoor or outdoor cats. A cat's veterinary care, diet and heredity also make a difference in how old they live to. Outdoor cats have a tendency to have shorter lives than indoor cats due to the dangers of the outdoors.