# ISO Fits vs Measurement Uncertainty GUM

ISO Fits and Measurement Uncertainty GUM are too close to call on the numbers: across 5 compared parameters — price, ads, in-app purchases and device support among them — neither pulls far enough ahead to decide it. What separates them is feature set and interface, not measurable difference.

Both are free to download. ISO Fits sells 1 one-off in-app purchase and Measurement Uncertainty GUM sells 2 in-app purchases, starting at $15.00 per month. Whichever you choose, the download price is not the number that matters.

## The numbers

| Metric | ISO Fits | Measurement Uncertainty GUM |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.2 (6 ratings)](https://appshunter.io/ios/app/iso-fits/id396863755/reviews)** | — |
| Number of ratings | **6** | — |
| Positive reviews | 94.6% of reviews | — |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | Every 5 months | — |
| Monetization | Free with in-app purchases | — |
| Size | 66 MB | 24 MB |
| Requires iOS | 15.6 | **15.0** |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Trelleborg Sealing Solutions](https://appshunter.io/developer/396863758) | [QAEE CONPUUTENG](https://appshunter.io/developer/1853582855) |

## What reviewers say

### ISO Fits

[App page](https://appshunter.io/ios/app/iso-fits/id396863755)

Calculate ISO fits and tolerances for shafts and bores. Supports metric and inch units, displays detailed fit definitions, and includes visual charts and educational videos.

**Highlights:** ISO fits calculation, Tolerance class display, Metric/inch unit switching, Tolerance charts, Updated YouTube videos

**Features:** macOS Compatibility

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Full Version with complete ISO286 Standard | $1.99 | one-time |


### Measurement Uncertainty GUM

[App page](https://appshunter.io/ios/app/measurement-uncertainty-gum/id6800986421)

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

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Uncertainty Pro Monthly | $15.00 | per month |
| Uncertainty Pro Yearly | $150.00 | per year |


## Frequently asked questions

### Is ISO Fits free?

ISO Fits is free to download, with in-app purchases available.

### Is Measurement Uncertainty GUM free?

Measurement Uncertainty GUM is free to download, with in-app purchases available.

### Do ISO Fits or Measurement Uncertainty GUM have ads?

Neither ISO Fits nor Measurement Uncertainty GUM shows ads.

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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.*