__Calculator for converting risk to odds and vice versa__ This calculator works off-line. (IE4) #### Programme written by DJR Hutchon.

Risk is expressed as a fraction i.e. 2 in 100 = .02

Odds is expressed as the ratio 20:80 = 0.25 while 80:20 = 4.0

Odds = Risk/(1-Risk) Explanation of odds and risk

Risk= Odds/(1+Odds)

This calculator is for educational use. It is believed accurate 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.

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 DJRHutchon@Postmaster.co.uk
1/10/1999

__Explanation of RISK and ODDS__

If stillbirth occurs in 15 pregnancies out of a total of 100 the risk of still birth is 15/100 or 0.15 . The odds of a stillbirth is the ratio of the number of stillbirths to the number of live births, that is 15/85 = 0.177. Thus one can say that the risk of stillbirth is, on average, fifteen out of every hudred pregnanies. For odds, for every 15 stillbirths there will be 85 livebirths.