# Virtual Flange Slide Rule vs Slug Calculation

The clearest difference is review sentiment: Virtual Flange Slide Rule at 100% against Slug Calculation's 0%. Virtual Flange Slide Rule also leads on price (Free vs $0.99) and update cadence (every 4 months vs every 39 months). On ads and in-app purchases there is nothing between them.

Virtual Flange Slide Rule is free to download; Slug Calculation costs $0.99 up front. Neither carries in-app purchases, so what you see is what you pay.

Virtual Flange Slide Rule ships an update every 4 months, Slug Calculation every 39 months. The most recent releases landed on October 23, 2026 and September 21, 2026 respectively.

## The numbers

| Metric | Virtual Flange Slide Rule | Slug Calculation |
| --- | --- | --- |
| Price | **Free** | $0.99 |
| Rating | **[5.0 (13 ratings)](https://appshunter.io/ios/app/virtual-flange-slide-rule/id546358145/reviews)** | — |
| Number of ratings | **13** | — |
| Positive reviews | **100.0% of reviews** | 0.0% of reviews |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Every 4 months** | Every 39 months |
| Monetization | **Free** | Paid |
| Size | 3 MB | 0 MB |
| Requires iOS | **15.0** | 17.0 |
| Devices | **iPhone, iPad, iPod** | iPhone |
| Age rating | 4+ | 4+ |
| Developer | [American Certified Equipment, Inc.](https://appshunter.io/developer/546358148) | [zhandos uakanov](https://appshunter.io/developer/625286817) |

## What reviewers say

### Virtual Flange Slide Rule

[App page](https://appshunter.io/ios/app/virtual-flange-slide-rule/id546358145)

Access essential measurements and dimensional data for API 6A integral flanges. This tool provides quick access to critical specifications for engineering and industrial applications.

**Highlights:** API 6A integral flange data, Relevant measurements, Dimensional data access, Engineering specifications

**Features:** macOS Compatibility

**In-app purchases:** none


### Slug Calculation

[App page](https://appshunter.io/ios/app/slug-calculation/id1292361542)

This app provides tools for enhanced oilfield drilling slug calculations. It helps determine the volume of slug needed to fill a pipe length and the weight of slug for a set volume, ensuring efficient operations.

**Highlights:** Slug Volume Calculation, Slug Weight Calculation, Streamlined interface, Practical design, Safety focused

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

**In-app purchases:** none


## Frequently asked questions

### Is Virtual Flange Slide Rule free?

Virtual Flange Slide Rule is free to download, with no in-app purchases.

### Is Slug Calculation free?

Slug Calculation costs $0.99, with no in-app purchases.

### Do Virtual Flange Slide Rule or Slug Calculation have ads?

Neither Virtual Flange Slide Rule nor Slug Calculation shows ads.

### Which is updated more often, Virtual Flange Slide Rule or Slug Calculation?

Virtual Flange Slide Rule ships an update every 4 months, and Slug Calculation every 39 months. Most recently, Virtual Flange Slide Rule was updated on October 23, 2026 and Slug Calculation on September 21, 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.*