I'll add that you should be able to place your right foot flat on the wall behind the brake pedal.

 

I am 5' 9" and I have found these cars to be very comfortable on a long trip. It took me several days of adjusting to get it right. When some one changes it I can usually get it back pretty quick. There is no way I can go three plus hours without stopping, being an old man I have to make a pit stop before that.

 

Each car manufacturer spends millions on ergonomics so that you will feel right at home the moment you slide into the seat...sells cars! Each time I do a street rod build, when setting up the seat I go to the family vehicles and measure brake pad to seat, steering wheel to seat vertically and to the back of the seat and "leg lift". Leg lift is how much higher the front of the seat is than the back of the seat. After checking several cars I find the measurements very close to one another. Only measurement I can't duplicate is seat distance off the floor but I find a little more tilt (more leg lift) makes it comfortable.

 

"Comfortable" is important, but you should still also consider cutting off the circulation to any Vulnerable area of your body.
That can vary from one person to another.

When you are 18-20 years old you can disregard all these seemingly silly adjustments.

Just Hop in and GO !!

SF