Real age of Hilary Swank in Buffy the Vampire Slayer
In the movie Buffy the Vampire Slayer, Hilary Swank was:
17 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 Buffy the Vampire Slayer was released:
January 1, 1992
And the day in which Hilary Swank was born:July 30, 1974
Since movies usually don't take more than one year to be released since the beginning of the filming process, Hilary Swank may have been one year younger or one year older than the shown age while some scenes of the movie were being filmed.