Not sure what you are trying to accomplish. You might do a search for
"calculate age" and you should find many posts (several from me) that
include the formula to calculate someone's age.
BUT.... You would not store this in your table. If you store a date in the
table, you don't also need to store the age (as it will change every year).
Calculated fields are redundant and should not be stored in the table. When
you need the calculation, you calculate it in your form, report, or query.
One other problem with trying to store a calculated field is what to do if
the original field changes. If you enter someone's birthday and calulate
their age, what happens if you find out the birthday is wrong and you
correct it?
Post an example and more details if this does not address your issue.
Rick B