There really is no standard length for a lanyard. I get measurements from my customers so that they get what fits them. There are a lot of differences that determine the length, height, neck size, a guy with a size 18 neck needs more length than one with a size 15, belly, guys with beer bellies want their lanyard either short or long so it hangs their way. I use a string and mark it with the length, where they want the drops etc..
Marvin