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)
Group 1 name -
Risk of in = Odds =
Convert back from Odds of Risk =
Group 2 name -
Risk of in = Odds =
Convert back from Odds of Risk =
Odds ratio Group1/Group2= Risk ratio Group1/Group2
A permanent record of the analysis can be obtained by printing the page.

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 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.