The distance between each joist mark varies depending on the specific tape measure, but typically you'll find them positioned 19.2 inches away from one another, usually dividing the tape measure ...

A tape measure is the single most-used tool on a ... furthest stand-out of the 1-inch tapes (the Milwaukee had 9 feet, 2 inches, and the Starrett has a bizarro-long 10 feet, 5 inches).