Calculator for customised birth weight at term and optimal fetal weight according to gestation. New Zealand population This calculator works off-line. (IE4)
Programme written by DJR Hutchon.

Maternal weight at booking =       Maternal height =
Fetal sex (m/f) (if not known leave blank)       Parity
Ethnicity =

Calculated optimal birth weight at term     = gm 10th to 90th centile gm

Enter specific gestation to obtain estimated optimal fetal weight at that gestation
GESTATION Weeks = + days = is         gm 10th to 90th centile gm
Expected fundal height cms 10th to 90th centiles

McCowan L, Stewart AW, Francis A, Gardosi J. A customised birthweight centile calculator developed for a New Zealand population. The University of Auckland and West Midlands Perinatal Institute, Birmingham, United Kingdom. Australian and New Zealand Journal of Obstetrics and Gynaecology 2004; 44: 428431
Gardosi J, Mongelli M, Chang A. An adjustable fetal weight standard. Ultrasound Obstet Gynecol 1995;6:168-174
See also CESDI 8th annual Report (2001).

This calculator is for educational use. It is believed to accurately apply the method of the above paper but no responsibility for accuracy of the results is accepted by the author. David J R Hutchon BSc, MB, ChB, FRCOG Consultant Gynaecologist, Memorial Hospital, Darlington, England. (Currently on sabbatical leave in Greymouth, New Zealand.
You are welcome to keep this page and use the calculator off-line. I would appreciate an E-mail if you find it useful enough to do so. E-mail to me at