1.shave the hair on ur head.hair can cause a lot of confusion.
2.make sure ur feet are smooth and healthy.feet fissures
can make u shorter by 1 cm.
3.measure yourself in cm first.because there can be a lot of confusion in conversions.
http://www.javascriptkit.com/script/script2/inchconvert.shtml
4.place a mirror in front while measuring.
5.stand against a wall which has markings on it.
6. take a scale(ruler)and place it over ur scalp.
7.note:make sure u place it over the peak of ur scalp.most scalps r round.
8.stand erect.
9.mark ur height on the wall. then stand exactly in the same place and check in the mirror if the marking is correct.
10. now measure ur height in cm using standard tape or scale.
11. a good site on human height
http://en.wikipedia.org/wiki/Human_height