chronological age

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. The number of years a person has lived, used especially in psychometrics as a standard against which certain variables, such as behavior and intelligence, are measured.

Wiktionary

1. n. the age of an individual measure in days, months and years from the time the individual was born, often used in psychometrics

WordNet 3.0

1. n. age measured by the time (years and months) that something or someone has existed