Only if your sit bones are as well padded as mine!!

Seriously though- my workstudy student ( a lovely young man, who rides
a cobalt blue Specializied Allez) had just earlier measured his sit bones in
order to shop for a new seat. He started with the find your bones & use
a tape measure method. He then tried the methods listed on the thread--he had a little trouble with the sit on concrete- (his sit bones are not as well padded.) He then successfully measured again using 2 markers----line up a marker on each bone- then lean/sit on a piece of paper. He was pleased
with this measurement.

From the home of the Fighting Okra