basic

Odds Ratio Calculator

OR = (a · d) / (b · c) from a 2 × 2 contingency table.

Compute the odds ratio from a 2×2 contingency table (exposed/non-exposed × outcome/no-outcome). OR > 1 means exposure is associated with higher odds of the outcome.

Daniel Oh By Daniel Oh
Published Last reviewed 1 min read

Inputs

Results

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How to use this calculator

  1. Fill in the inputs above using the units you already have.
  2. Values update automatically as you type — no submit button needed.
  3. Hover any result row for the underlying formula and intermediate values.

Formula

OR = (a · d) / (b · c)

In depth

Compute the odds ratio from a 2×2 contingency table (exposed/non-exposed × outcome/no-outcome). OR > 1 means exposure is associated with higher odds of the outcome.