chronological age

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun 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.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun the age of an individual measure in days, months and years from the time the individual was born, often used in psychometrics

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun age measured by the time (years and months) that something or someone has existed