Real age of John Wayne in True Grit
In the movie True Grit, John Wayne was:
61 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 True Grit was released:
January 1, 1969
And the day in which John Wayne was born:May 26, 1907
Since movies usually don't take more than one year to be released since the beginning of the filming process, John Wayne may have been one year younger or one year older than the shown age while some scenes of the movie were being filmed.