FREE TOOLS
Instant calculators for the formulas behind every meta-analysis — no account, no sign-up, free to use.
Every meta-analysis rests on the same handful of calculations, repeated across dozens of studies: how much does the effect vary from study to study, how large is the effect in a single study, and how many participants does a planned study need to detect a real difference. These three calculators isolate each of those questions so you can check a number, sanity-check a reviewer's calculation, or plan a study without opening a full statistics package or building a spreadsheet from scratch.
Compute Cochran's Q, I², and τ² from a list of study effect sizes and standard errors.
Cohen's d, Hedges' g from means and SDs, or odds ratio, risk ratio, and risk difference from a 2×2 table.
Required participants per group to detect a difference between two proportions or two means.
FAQ
Yes. All three tools run entirely in your browser — there's no account, no sign-up, and no usage limit. Nothing you enter is sent to a server.
The I² calculator uses Cochran's Q and the standard DerSimonian-Laird τ² estimator. The effect size calculator uses Woolf's method with a 0.5 continuity correction for dichotomous data, and Cohen's d / Hedges' g (with the small-sample J correction) for continuous data. The sample size calculator uses the standard two-proportion and two-mean power formulas with an exact normal quantile (Acklam's algorithm) rather than a rounded table lookup.
Yes — the formulas match the conventions used in Cochrane Review Manager and most published meta-analyses. For a full review with many studies, subgroup analysis, and forest plots, EvidenceFlow's full meta-analysis workspace builds on the same statistics with study-level tracking and reporting.
No. Each tool asks for the numbers you already have — study effect sizes and standard errors, group means and sample sizes, or a 2×2 event table — and returns the result with a short explanation of what it means.