G*Power review
A focused, free tool for power analysis and sample-size planning.
Reviewed by iTechGuides Editors · Editorial team · Updated Oct 2026
G*Power is desktop software for statistical power analysis and study planning. It is intended for researchers, students, and educators who need to calculate power, estimate sample sizes, examine effect sizes, or document analysis decisions. The software covers t tests, F tests, chi-square tests, z tests, and exact tests, making it useful across several common study-design scenarios. It runs locally on Windows and macOS and is distributed free of charge by Heinrich-Heine-Universität Düsseldorf.
Its standout strength is the range of planning modes within a focused tool. Users can perform a priori, compromise, criterion, post-hoc, and sensitivity analyses, then review graphical power plots and tabular results. Effect-size calculators, central and noncentral probability distribution functions, and a calculator with a documented script interface extend the planning workflow. An analysis protocol can also be saved, printed, or copied, which supports clearer records of study assumptions and results. This depth makes G*Power a strong fit when power analysis is the main requirement rather than one feature inside a larger statistics environment.
The pricing structure is straightforward: the Free plan is available to everyone, including commercial users, with local desktop applications for Windows and macOS. That makes it accessible for independent researchers, classrooms, and teams that need dedicated power-planning software without a subscription. The trade-off is scope. G*Power is a narrow statistical analysis product rather than a general-purpose package, and it does not include AI features. Choose it for free, detailed power and sample-size planning; choose an alternative when your work depends on a broader analysis environment or a wider range of integrated capabilities.
G*Power pros and cons
- Where it wins
- Supports power analyses across t, F, chi-square, z, and exact tests
- Includes effect-size calculators, plots, distributions, and tabular results
- Free desktop software for Windows and macOS, including commercial users
- Where it doesn't
- Focused on power analysis rather than broad statistical analysis
- Local desktop deployment may not suit browser-based workflows
- No AI features are included
G*Power fact sheet, pricing and score →
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