Age Formula for Forms in Zoho People

Age Formula for Forms in Zoho People

Hi, 

I have created an employee details form in Zoho People. I have a field for "Date of birth". How do I use the formula function, to create an auto-generated Age field?

I have tried searching for the formula in the forum, but none of it works. I might do it wrongly. If anyone could help me that would be great!

Aiman