Real age of Katherine Heigl in 100 Girls
In the movie 100 Girls, Katherine Heigl was:
21 years old
That was the real age of the celebrity according to our calculation.
The calculation of the shown age took into account the first day of the year in which the movie 100 Girls was released:
January 1, 2000
And the day in which Katherine Heigl was born:November 24, 1978
Since movies usually don't take more than one year to be released since the beginning of the filming process, Katherine Heigl may have been one year younger or one year older than the shown age while some scenes of the movie were being filmed.