With the latest update, this calculator does everything that anyone could expect of a tool designed for obstetric providers including things like arriving at gestational age from various fetal ultrasound measurements. Other gestational age calculators are also apparently designed by engineers for lay people who dont know anything about obstetrics or significant figures (as they show "estimated" fetal weights and such down to the gram - yeah right).
You dont need to look any further for a calculator if you take care of pregnant women.
Another_OB_DOC about The Wheel SP