Logistic Odds Ratio
Computes odds ratio from logistic regression beta coefficient.
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Turning a logistic beta into an odds ratio
R, Stata and SPSS report logistic regression coefficients on the log-odds scale, and the journal wants odds ratios. It is one exponential and nothing more, yet nobody wants to open a console mid-paragraph just to work out exp(0.5). Type the beta and the page returns the odds ratio to four decimal places, updated on every keystroke, with no intermediate step.
The calculation is exp(β). A beta of 0 gives an OR of 1, meaning no association; positive betas rise above 1 and negative ones fall between 0 and 1, so −0.69 comes back as 0.5017, roughly halved odds. Keep the unit in mind, because exp(β) is the odds ratio for a one-unit increase in the predictor. If that predictor is age in years, a ten-year effect is exp(10β), not ten times the OR. The field accepts betas from −10 to 10.
There is no confidence interval here, and an OR without one will not survive peer review. Given the standard error, the bounds are exp(β ± 1.96 × SE), and you can read both off by entering each bound as a separate beta. Watch the wording too: an odds ratio is not a relative risk, and the two diverge badly when the outcome is common. For categorical predictors the OR always refers to the model's reference category. All of it runs in the browser.
Frequently asked questions
Does an OR of 1.6487 mean 65% more risk?
How do I get the confidence interval?
Can I use it for a Cox coefficient?
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The results provided by this tool are for general informational and educational purposes only and do not constitute professional, financial, medical, legal, tax or accounting advice. Always confirm important decisions with a qualified professional and official sources.