J'ai vingt-six ans

yes it would be really wrong to say je suis 26 ans. It's very very odd in french. We say "I have 26 years old."

Oh thank you. Maybe there is a certain rule about this. Is it wrong if I say Je suis vingt-six ans?

Je suis = I am J'ai = I have

merci! but what is the difference between Je suis and J'ai? Do they both mean I am? Can't I use Je suis in this sentence? Merci!