This restrictions is usually measured in INCHES rather than feet.
Altho it may vary from juriisdiction-to-jurisdiction depending on the local laws a GENERAL rule of thumb is NO MORE than 12 inches.
18 inches from the curb.
12
The car did not park on the curb
you may not park next to a curb that is painted red.
From the Calfornia DMV web page on parking: When you park alongside a curb on a level street, the front and back wheels must be parallel and within 18 inches of the curb. Park parallel to the street if there is no curb.
You want the back axles if trailer as close as you can to curb
You should park your car less than six inches away from the curb.
Towards the curb.
Parking more than 12 inches from the curb canresult in a ticket in Washington state(RCW 46.61.575)
the maxium is 6 inches but it has been debated by many if it is more
15 feet
I try hard to park within 6" of the curb. If it's a tight squeeze it's not always possible. I do hate rubbing my tires against the curb, or parking with more than a foot of space between wheels and curb.