To
get your sleeve length by
standing, start measuring from
the centre of your shoulder,
just past your wrist. Your
measurement will be more
accurate should you keep your
arm straight.
To get your sleeve length from a
shirt you already have, measure
the length of a well fitting
shirt from the centre of the
shoulder to the bottom of the
cuff. Make you're your shirt is
flat so you get the most
accurate measurement.