Statistics

Relative Risk Odds Ratio Calculator

Compute RR, OR, and confidence intervals from a 2x2 contingency table.

Last validated: 2026-02-14

Relative Risk Odds Ratio Calculator derives RR and OR from 2x2 outcome tables. It is useful in epidemiology, A/B analysis, and risk comparison studies. The tool converts contingency counts into interpretable effect measures. Use it to compare exposure and outcome relationships.

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Input Pattern

Enter values in the left panel, keep units explicit, run the calculation, then copy or share the result. Invalid fields are highlighted immediately.

2x2 Table Inputs

a=exposed+outcome, b=exposed+no outcome, c=unexposed+outcome, d=unexposed+no outcome

Result

Risk exposed: 0.450000

Risk unexposed: 0.200000

Relative risk: 2.25000000

RR 95% CI: 1.437687 to 3.521281

Odds ratio: 3.27272727

OR 95% CI: 1.745242 to 6.137109

How to use this tool

Enter counts for exposed/unexposed and outcome/no-outcome cells.
Run the tool to compute RR and OR values.
Interpret effect size with confidence intervals where available.

Worked Example

Auto-generated from the tool's current default or entered inputs.

Example Inputs

A: 45
B: 55
C: 20
D: 80
Adjusted:
Risk exposed: 0.45
Risk unexposed: 0.2
Relative risk: 2.25

Expected Outputs

A: 45
B: 55
C: 20
D: 80

Interpretation

A is 45. Use this as a decision input, not as a standalone conclusion.
B is 55. Use this as a decision input, not as a standalone conclusion.
C is 20. Use this as a decision input, not as a standalone conclusion.
Interpret this value alongside sample quality and assumptions to avoid overconfidence.

Scenario Compare (A vs B)

Use this to compare two input sets and quantify change in key outputs.

Scenario A

Adjusted

Risk exposed

Risk unexposed

Relative risk

Scenario B

Adjusted

Risk exposed

Risk unexposed

Relative risk

Confidence and limitations

Outputs are deterministic formula results and depend entirely on input quality and units.
Results are for planning and learning; verify with domain standards before safety-critical use.
Interpretation depends on assumptions (distribution, independence, sample quality).

Formula References

Frequentist estimation and hypothesis-test formulas used in standard textbooks.
Interpretation depends on sample quality and assumptions.

Assumptions

Outputs are deterministic formula results and depend entirely on input quality and units.
Results are for planning and learning; verify with domain standards before safety-critical use.
Interpretation depends on assumptions (distribution, independence, sample quality).

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