If cat is 11 how old that in years?

This is a bit tricky! Cats age differently than humans.

* The first year of a cat's life is equivalent to about 15 human years.

* The second year is roughly equal to 9 human years.

* After that, each cat year is about 4 human years.

So, it's not a simple conversion. To get a more accurate estimate, you'd need to know the cat's exact age in cat years.

Let me know if you have a specific cat age in cat years, and I can try to help you figure out the human equivalent!