FREE TOOL
Meta-analysis calculator
Pool effect estimates and standard errors with fixed-effect or random-effects inverse-variance methods. Calculations happen in your browser; no account required.
Pooled estimate
0.428 [95% CI 0.294, 0.562]
Studies: 3 · Q: 0.90 · I²: 0.0% · τ²: 0.0000
Methods and interpretation
Fixed-effect pooling uses inverse-variance weights (1/SE²). The random-effects option estimates between-study variance with the DerSimonian–Laird method and uses weights 1/(SE² + τ²). The displayed confidence interval uses a normal approximation.
Cochran’s Q and I² describe statistical heterogeneity; τ² is the estimated between-study variance. These statistics do not explain why studies differ and should be interpreted alongside clinical and methodological differences.
FAQ
Frequently asked questions
What effect measures can I pool?+
Any effect measure with compatible scale and standard errors, such as mean differences, standardized mean differences, or log odds ratios. Do not mix different measures or scales.
Which random-effects method is used?+
The calculator uses DerSimonian–Laird τ² with inverse-variance weights and a normal-approximation confidence interval.
Does I² tell me whether studies are clinically different?+
No. I² summarizes the proportion of observed variation attributed to between-study heterogeneity under the model. It does not assess clinical importance or explain causes.
Use EvidenceFlow to keep extracted study data, risk-of-bias judgments, and meta-analysis results together in a review workspace.
Start free project