# Calculate Standard Deviation vs Epi Tools

The clearest difference is review sentiment: Epi Tools at 100% against Calculate Standard Deviation's 50%. Epi Tools also leads on rating (5.0 vs 4.5) and in-app purchases (none vs 1). Calculate Standard Deviation's advantage is ratings volume (62 vs 1). On price and device support there is nothing between them.

Both are free to download. Calculate Standard Deviation sells 1 one-off in-app purchase. Epi Tools asks for nothing beyond the download.

Epi Tools holds the better App Store score, 5.0 against 4.5. That said, the two scores are not equally well evidenced: Calculate Standard Deviation has 62 ratings behind it against 1, so its average is the more settled of the two. Written reviews point the same way: 50% of Calculate Standard Deviation's written reviews are positive against 100% of Epi Tools's.

Calculate Standard Deviation ships an update every 7 months, Epi Tools every 2 months. Both last shipped on November 3, 2026.

## The numbers

| Metric | Calculate Standard Deviation | Epi Tools |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [4.5 (62 ratings)](https://appshunter.io/ios/app/calculate-standard-deviation/id1591420646/reviews) | **[5.0 (1 ratings)](https://appshunter.io/ios/app/epi-tools/id1611139482/reviews)** |
| Number of ratings | **62** | 1 |
| Positive reviews | 50.0% of reviews | **100.0% of reviews** |
| In-app purchases | Yes | **No** |
| Ads | Yes | **No** |
| Update frequency | Every 7 months | **Every 2 months** |
| Monetization | Free with in-app purchases | **Free** |
| Size | 39 MB | 19 MB |
| Requires iOS | 15.0 | **13.4** |
| Devices | **iPhone, iPad, iPod** | iPhone, iPod |
| Age rating | 4+ | 12+ |
| Developer | [Asad Ahsan](https://appshunter.io/developer/1326954499) | [Mark Stevenson](https://appshunter.io/developer/1611139484) |

## What reviewers say

### Calculate Standard Deviation

[App page](https://appshunter.io/ios/app/calculate-standard-deviation/id1591420646)

This app calculates standard deviation, variance, and other statistical measures for a given set of values. It simplifies complex statistical formulas with a user-friendly interface and accurate results.

**Highlights:** Calculate Standard Deviation, Calculate Variance, Calculate Mean, Calculate Coefficient of Variance, Calculate Standard Error of Mean, User-friendly interface, Accurate statistical results

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Standard Deviation Premium | $4.99 | one-time |


### Epi Tools

[App page](https://appshunter.io/ios/app/epi-tools/id1611139482)

This app provides a suite of epidemiological calculation tools for disease frequency, association, and effect measures. It also includes sample size calculators, diagnostic test validation, and a comprehensive glossary of terms.

**Highlights:** Measures of disease frequency with confidence intervals, Measures of association and effect, Sample size calculators, Diagnostic test validation, Post-test probability estimation, Random number generator, Epidemiology glossary

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases:** none


## Frequently asked questions

### Is Calculate Standard Deviation free?

Calculate Standard Deviation is free to download, with in-app purchases available.

### Is Epi Tools free?

Epi Tools is free to download, with no in-app purchases.

### Which has better reviews, Calculate Standard Deviation or Epi Tools?

Epi Tools is rated higher. Calculate Standard Deviation averages 4.5 out of 5 from 62 ratings, while Epi Tools averages 5.0 from 1 ratings.

### Do Calculate Standard Deviation or Epi Tools have ads?

Calculate Standard Deviation shows ads; Epi Tools does not.

### Which is updated more often, Calculate Standard Deviation or Epi Tools?

Calculate Standard Deviation ships an update every 7 months, and Epi Tools every 2 months. Most recently, Calculate Standard Deviation was updated on November 3, 2026 and Epi Tools on November 3, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*