RR / OR / NNT Calculator — free, runs in your browser
Enter a 2×2 table to compute relative risk RR, odds ratio OR, absolute risk difference ARD, relative risk reduction RRR and number needed to treat NNT, … Computed in your browser — no data uploaded.
Open free tool →Runs in your browser
No software installation. Paste your data and get results instantly.
Publication-ready output
Export charts as SVG vector or HD/UHD PNG suitable for journal submission.
Data stays local
Nothing is uploaded. Your patient data never leaves your device.
Common questions
What are the original references?
Altman DG. BMJ 1998;317:1309-12. PMID 9804726.
When should I use RR?
Enter a 2×2 table to compute relative risk RR, odds ratio OR, absolute risk difference ARD, relative risk reduction RRR and number needed to treat NNT, with 95% CIs for ratios and the risk difference. Common for interpreting cohort/case-control/RC…
Is my data safe?
All calculations run entirely in your browser. No data is sent to any server. You can even use the tool offline after the page loads.
Run RR now
Enter a 2×2 table to compute relative risk RR, odds ratio OR, absolute risk difference ARD, relative risk reduction RRR and number needed to treat NNT, … Computed in your browser — no data uploaded.
Open free tool →Free to use. No account required. No data uploaded.
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