Odds Ratio Calculator
Calculate the odds ratio from a 2x2 contingency table
2x2 Contingency Table:
| Outcome (+) | Outcome (-) | |
|---|---|---|
| Exposed | ||
| Not Exposed |
About Odds Ratio
The odds ratio compares the odds of an outcome between two groups, commonly used in case-control studies and epidemiology.
Formula: OR = (a × d) / (b × c)
Interpretation:
- OR = 1: No association
- OR > 1: Exposure increases odds of outcome
- OR < 1: Exposure decreases odds of outcome
Note: OR approximates relative risk when outcome is rare (<10%).
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Editorial Note
MyCalcBuddy Editorial Team
This page is maintained as an educational calculator reference.
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Formula Source: Standard Mathematical References
by Various
🔄Last reviewed: May 2026
✓Formula checks are based on standard references and internal QA review.