7-1/4 in. (58 European).
The hat they wear is called a fedora.
I don't know. Maybe that was the only color hat that they had on set?
The hat Henry Jones wears is believed to be a tweed "walking hat".
His hat.
no time at all
Indiana Jones' iconic hat is typically made of felt, specifically wool felt, which gives it a durable yet pliable quality. In the films, the hat is often portrayed as a fedora, characterized by its wide brim and creased crown. The choice of felt material contributes to the hat's rugged appearance, fitting for the adventurous character of Indiana Jones.
His "regular" clothes aside, his hat is a trademark second only to his whip (which he may or may not be seen to "wear" as it is sometimes clipped to his waist).
whip hat
A fedora hat.
Indiana Jones' hat is a take on fedora hats popular during the period of the films. Jones' fedora is a brown color, a bit more broader with a taller crown, but falls between a traditional fedora and an Australian outback hat.
The Herbert Johnson Hat Co. of Saville Row, London.
whip hat shosr