Interpret study results fast.

Evidence-based medicine calculators for iPhone, iPad, and Mac. Built to support your critical appraisal of the medical literature.

Designed and built by David A. Stewart, MD

EBM Calculator showing effect estimates with a 2×2 contingency table, NNT, RR, OR, and 95% confidence intervals, with the source study cited below

What's inside

Effect Size Calculator

ARR, NNT, RR, RRR, and OR with 95% confidence intervals — for studies of therapy or exposure with dichotomous outcomes.

Diagnostic Test Calculator

Sensitivity, specificity, likelihood ratios, and predictive values with 95% confidence intervals — for diagnostic accuracy studies.

Post-Test Probability

Visualize how a test result shifts the probability of disease with an interactive Fagan nomogram.

Save, Search & Share

Save unlimited results on device. Search, sort, and filter to find what matters. Share as a clean PNG for messages and email, or export .ebmc files to other EBM Calculator users.

Citations

Attach citations by PubMed ID (PMID) with one tap, or enter them by hand.

Lessons

Built-in lessons in evidence-based medicine and biostatistics — searchable by title or keyword — reinforce the concepts behind every calculation.

Guided Tutorials

Step-by-step in-app tutorials walk you through every major feature. Open from the menu in any view, or from Settings.

iCloud Sync

Saved results sync automatically across all your devices through your personal iCloud account.