my kilts are all differnt lengths.
my latest still water is toward the lower part of my knee, others like my leather "r-kilt" I wanted to try it a bit shorter.
IMHO the middle of the knee looks best.
and a few inches above the knee, does look a bit "skirty" to me, but that's just MY opinion.
do whatever you think is best for you.
there are no rules.
the original scottish way of thinking was , your kilt should not touch the floor as you kneel to pray.
I agree with bcmtnbka
if I wear a longer kilt I tend to wear boots.
and with shorter kilts I wear kilt sox.
or there would be no gap between kilt and sox.
for me, this is a "no, no"