Have you ever wondered how old your cat would be if it were human? It may seem strange, but you may find your cat is much older than you.
A cat's age is generally determined by examining the condition of its teeth. In kittens the extent of the growth is measured and in older cats the wear and tear present on the teeth is graded. Complex charts are available that help this information to be translated into cat ages as measured in years1.
The lifespan of a cat is quite different from that of a human and so even with the knowledge of a cat's age in years, this means little if comparisons are being made to a human lifespan. In other words, knowing how old your cat is doesn't tell you in what stage of its life your cat would be if it were human.
Comparing Cat to Human Ages
Traditionally, folklore states that one human year is equal to seven cat or dog years, but this does not receive support from current theories of how cats develop. According to the traditional comparison, an 18-year-old cat would actually be 126 years old if it were a human2.
Current estimates comparing a cat's lifespan to human years shows the relationship is not linear; in other words the age comparison changes, as the cat grows older3. All comparisons are subjective which means that they are estimated and may vary.
A Chart to Show Comparison of Cat to Human Ages
The chart below shows cat ages in human years. For example a two-year-old cat would be similar to a human at 25 years old. You can see that it is generally believed that a cat ages more quickly earlier in its life, slowing down as it gets older, when compared to human ageing.
| CAT | 1 month | 2 months | 3 months | 4 months | 5 months | 6 months |
| HUMAN | 6 months | 10 months | 4 years | 5.5 years | 8.5 years | 11.5 years |
| | | | | | | |
| CAT | 7 months | 8 months | 9 months | 10 months | 11 months | 1 year |
| HUMAN | 13 years | 13 years | 13 years | 14 years | 14.5 years | 16 years |
| | | | | | | |
| CAT | 2 years | 3 years | 4 years | 5 years | 6 years | 7 years |
| HUMAN | 25 years | 31 years | 35 years | 38.5 years | 41 years | 46.5 years |
| | | | | | | |
| CAT | 8 years | 9 years | 10 years | 11 years | 12 years | 13 years |
| HUMAN | 49 years | 54 years | 58 years | 61 years | 64.5 years | 68.5 years |
| | | | | | | |
| CAT | 14 years | 15 years | 16 years | 17 years | 18 years | 19 years |
| HUMAN | 72 years | 75 years | 78 years | 79 years | 85 years | 86 years |
The chart is a summary obtained by reviewing eight different sources listing estimated cat to human age comparisons4 and taking a mean estimate from these sources. The mean being the sum of the ages divided by the number of ages.
These ages are with reference to a cat's physical age rather than their emotional age as many domestic cats exhibit classical kitten behaviour throughout their adult years as a result of their environment.
1 1999 The Humane Society of the United States.
2 1983 Simon and Schuster's Guide to Cats.
3 From NCTM.com.
4 The raw data used to compute the estimates for the chart was sourced from - The Cat Basket, Glenda Moore's Cat Stuff, Companion Animal Clinic, Metpet.com, NCTM.com, Companion Animal Resource Education Information Center, Jovisca Cattery, and the Rabbit Information service.
