look up the average pace of the finish, do math. note: people have brought up aid station time, which, yes if you spent like 30 minutes at each this would being mid pack finishers up into the 'mostly running range' but its still amortized walking pace.

This isn't meant to suggest that 100milers are easy or dumb, just that if you imagine someone actually running 100 miles straight and think that sounds nearly impossible, it is. Most people aren't doing that. If you think a 100 miler sounds interesting, you should try it, because you can probably do it. But please prepare really well because it is going to be really hard.