In the United States, it is illegal for a potential employer to ask, “how old are you?” in an interview. However, no law prevents them from asking for age/date of birth on a job application or background check form. So it is possible that they already know your age entering the conversation. Note, this may vary from country to country and even state to state.
Luckily, if the question gets brought up, there are ways around it. I encourage you to shift the focus away from age and focus on the skills and invaluable experience you can bring to the team!
Here are some examples:
I am confident that my years of experience in this area, coupled with my continued passion for learning, will make me an asset to your team! Former employers have embraced age diversity and valued it. Am I correct to think that [COMPANY X] shares the same mindset?
Is there a concern about some skill sets or education related to this position? I am confident that my past experiences and accomplishments make me an ideal candidate for this role. I’d love to briefly highlight some recent projects to demonstrate my ability to succeed in this position!
Ideally, the interviewer will realize what they asked was inappropriate. How they react will also say a lot about the company’s philosophy on diversity.