If you read the fine print on the www.cheezit.org.net.com you find a disclaimer that production CheezIt's are not intended as precision measuring devices. The only accurately calibrated CheezIt is held at the National Beaureu of Standards. Some other interesting standards held at this facility are:
Dogs Hind Leg (crookedness measurement)
Shit Load (dry measure)
Whole Nine Yards (completeness)
Witches Tit (cryogenics)