# BioStat Lab — Sample Size & Power Calculator

> Sample Size & Power Calculator (iPhone/iPad app by 长贵 周.)

- Source: https://appshunter.io/ios/app/biostat-lab/id6784252840 (this page in markdown: same URL + `.md`)
- Developer: [长贵 周](https://appshunter.io/developer/6779968395)
- Category: Medical, Utilities
- Price: Free
- Age rating: 4+
- Requires: iOS 17.0 · 2 MB
- Languages: American English, French (France), German (Germany), Japanese, Korean, Brazilian Portuguese, Chinese (Simplified, China), European Spanish, Chinese (Traditional, Taiwan)
- Released: 2026-06-30
- Data updated: 2026-08-04
- User reviews in markdown: https://appshunter.io/ios/app/biostat-lab/id6784252840/reviews.md

## What is BioStat Lab?

BioStat Lab is a precise, offline statistical power and sample size calculator designed for biomedical researchers, clinicians, and students.

CALCULATORS INCLUDED

t-Test — Independent & Paired
Calculate the required sample size for independent-samples or paired t-tests. Enter mean difference, standard deviation, significance level (α), and desired power (1−β).

ANOVA — One-Way
Determine per-group and total sample size for a one-way ANOVA across 2–20 groups. Uses Bonferroni-adjusted alpha for multiple-comparison control.

Proportions — Two-Proportion z-Test
Compare two event rates or response proportions. Displays absolute difference and risk ratio alongside the required sample size per group.

Correlation — Pearson r
Sample size for testing whether a Pearson correlation is significantly different from zero. Uses Fisher z-transformation for accuracy. Includes Cohen's effect-size classification.

Survival — Log-Rank Test
Event-driven sample size for survival studies using Freedman's formula. Enter hazard ratio, expected event rate, α, and power to get required events and total subjects.

DESIGN PHILOSOPHY
Dark space-inspired interface — deep indigo background, violet accent readouts, monospaced numeric displays — optimized for focused scientific work.

PRIVACY
No account required. No data collected. All calculations happen on-device.


## Version history (last 1 release)

### 1.0 — 2026-07-01

No release notes.

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All apps by 长贵 周: https://appshunter.io/developer/6779968395

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-08-04.*