Using calculated field in query to update table (1 Viewer)

Hi all, this is my first post as a member. I'm hoping someone can help me.
I have run a simple query from a table (tb_customers) to calculate age from DoB. This query has been successful.

I now want to put the results of this calculated field called 'age' ( in the query) into a new column in tbl_customers

Can someone please help me with how I should do this update query

Many thanks

NEVER put a calculated field , like age , in a table field.
ALWAYS keep it calculated.

To expand on Ranman's answer, any calculated age will go out of date so its wrong to store that as a field in a table. Instead use an expression or function to calculate the age as and when needed for display in a form etc