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Centre for Evidence-
Based Medicine

Odds Ratio to NNT Converter

Note: This calculator requires JavaScript. Please ensure that you are using an up-to-date browser with JavaScript turned on. If you have technical difficulties, please contact david.newton@utoronto.ca.

The OR to NNT Converter was created for your own personal use and testing purposes. It is to be used as a guide only. Medical decisions should NOT be based solely on the results of this program. Although this program has been tested thoroughly, the accuracy of the information cannot be guaranteed.

This calculator is also available in a Palm OS version.

To convert odds ratios to NNTs, enter a number that is > 1 or < 1 in the odds ratio textbox and a number that is not equal to 0 or 1 for the Patient's Expected Event Rate (PEER). After entering the numbers, click "Calculate" to convert the odds ratio to NNT.

CEBM Odds Ratio to NNT Converter