# ProEngineer Calculator vs Reliability Pro

The clearest difference is price: Reliability Pro at Free against ProEngineer Calculator's $19.99. Reliability Pro also leads on update cadence (every 4 days vs monthly). ProEngineer Calculator's advantage is in-app purchases (none vs 2). On rating, review sentiment, ratings volume and ads there is nothing between them.

Reliability Pro is free to download; ProEngineer Calculator costs $19.99 up front. Reliability Pro sells 2 in-app purchases, starting at $14.99 per month. ProEngineer Calculator asks for nothing beyond the download.

On the App Store both sit at effectively the same score — 5.0 for ProEngineer Calculator against 5.0 for Reliability Pro. Both are backed by a comparable volume of ratings — 1 and 2 respectively. Written reviews split almost evenly too, at 100% and 100% positive.

ProEngineer Calculator ships an update monthly, Reliability Pro every 4 days. The most recent releases landed on October 4, 2026 and October 5, 2026 respectively.

## The numbers

| Metric | ProEngineer Calculator | Reliability Pro |
| --- | --- | --- |
| Price | $19.99 | **Free** |
| Rating | [5.0 (1 ratings)](https://appshunter.io/ios/app/proengineer-calculator/id6752825468/reviews) | [5.0 (2 ratings)](https://appshunter.io/ios/app/reliability-pro/id6782085318/reviews) |
| Number of ratings | 1 | **2** |
| Positive reviews | 100.0% of reviews | 100.0% of reviews |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Monthly | **Every 4 days** |
| Monetization | **Paid** | Subscription |
| Size | 46 MB | 75 MB |
| Requires iOS | 15.1 | **15.0** |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Margaret Hayes](https://appshunter.io/developer/1840974547) | [Illayathambi Kunadian](https://appshunter.io/developer/6782085321) |

## What reviewers say

### ProEngineer Calculator

[App page](https://appshunter.io/ios/app/proengineer-calculator/id6752825468)

This app provides engineers and students with a comprehensive suite of tools for complex calculations across various engineering disciplines. It offers features for stoichiometry, thermodynamics, electrical, and fluid mechanics, along with process visualization and project management aids.

**Highlights:** Stoichiometry & Material Balances, Thermodynamics Calculations, Electrical Calculations, Flow Mechanics Calculator, Process Timeline, Consultant Directory

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

**In-app purchases:** none


### Reliability Pro

[App page](https://appshunter.io/ios/app/reliability-pro/id6782085318)

This app offers a comprehensive suite of over 75 professional tools for reliability, quality, and statistics analysis. It includes advanced features like life-data analysis, system modeling, and SPC control charts, all accessible on mobile devices with step-by-step tutorials and an AI assistant.

**Highlights:** 75+ reliability, quality, and statistics tools, AI assistant for tool discovery, Step-by-step video tutorials, Reference library with theory and formulas, Data import and export (PDF, text), Verified tools against industry standards

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

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Reliability Pro Monthly | $14.99 | per month |
| Reliability Pro Annual | $99.99 | per year |


## Frequently asked questions

### Is ProEngineer Calculator free?

ProEngineer Calculator costs $19.99, with no in-app purchases.

### Is Reliability Pro free?

Reliability Pro is free to download, with in-app purchases available.

### Which has better reviews, ProEngineer Calculator or Reliability Pro?

ProEngineer Calculator and Reliability Pro are both rated 5.0 out of 5 on the App Store, from 1 and 2 ratings respectively.

### Do ProEngineer Calculator or Reliability Pro have ads?

Neither ProEngineer Calculator nor Reliability Pro shows ads.

### Which is updated more often, ProEngineer Calculator or Reliability Pro?

ProEngineer Calculator ships an update monthly, and Reliability Pro every 4 days. Most recently, ProEngineer Calculator was updated on October 4, 2026 and Reliability Pro on October 5, 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.*