# iAttenuation vs DOT Chart 17

The clearest difference is price: DOT Chart 17 at Free against iAttenuation's $2.99. DOT Chart 17 also leads on update cadence (every 10 months vs every 69 months) and iOS requirement (11.0 vs 15.6). iAttenuation's advantage is rating (3.0 vs 2.3). On ratings volume, ads, in-app purchases and device support there is nothing between them.

DOT Chart 17 is free to download; iAttenuation costs $2.99 up front. Neither carries in-app purchases, so what you see is what you pay.

iAttenuation holds the better App Store score, 3.0 against 2.3. Both are backed by a comparable volume of ratings — 2 and 3 respectively.

iAttenuation ships an update every 69 months, DOT Chart 17 every 10 months. The most recent releases landed on October 5, 2026 and October 10, 2026 respectively.

## The numbers

| Metric | iAttenuation | DOT Chart 17 |
| --- | --- | --- |
| Price | $2.99 | **Free** |
| Rating | **[3.0 (2 ratings)](https://appshunter.io/ios/app/iattenuation/id305626528/reviews)** | [2.3 (3 ratings)](https://appshunter.io/ios/app/dot-chart-17/id1245251292/reviews) |
| Number of ratings | 2 | **3** |
| Positive reviews | — | 0.0% of reviews |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 69 months | **Every 10 months** |
| Monetization | Paid | **Free** |
| Size | 1 MB | 20 MB |
| Requires iOS | 15.6 | **11.0** |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Black Cat Systems](https://appshunter.io/developer/301047032) | [Pipeline and Hazardous Materials Safety Administration](https://appshunter.io/developer/954888820) |

## What reviewers say

### iAttenuation

[App page](https://appshunter.io/ios/app/iattenuation/id305626528)

This app calculates resistor values for various passive attenuator networks. It supports T, Pi, H, O, and Minimum Loss Pad configurations, allowing users to input impedance and desired attenuation. It can also adjust resistor values to standard tolerances.

**Highlights:** Calculates resistor values for passive attenuator networks, Supports Tee, Pi, H, O, and Minimum Loss Pad configurations, Input and output impedance calculation, Desired attenuation input, Adjusts resistor values to standard tolerances (1%, 5%, 10%)

**Features:** macOS Compatibility

**In-app purchases:** none


### DOT Chart 17

[App page](https://appshunter.io/ios/app/dot-chart-17/id1245251292)

Access a full-color display of hazardous materials markings, labels, and placards. This app provides quick visual information and regulatory citations for shippers and carriers. It serves as a general guidance tool for hazardous materials regulations.

**Highlights:** Full-color display of markings, labels, and placards, Access to Hazardous Materials Regulations (HMR) citations, Quick visual information for shippers and carriers, Mobile access to DOT Chart-17, Guidance on 49 CFR Parts 171-180

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

**In-app purchases:** none


## Frequently asked questions

### Is iAttenuation free?

iAttenuation costs $2.99, with no in-app purchases.

### Is DOT Chart 17 free?

DOT Chart 17 is free to download, with no in-app purchases.

### Which has better reviews, iAttenuation or DOT Chart 17?

iAttenuation is rated higher. iAttenuation averages 3.0 out of 5 from 2 ratings, while DOT Chart 17 averages 2.3 from 3 ratings.

### Do iAttenuation or DOT Chart 17 have ads?

Neither iAttenuation nor DOT Chart 17 shows ads.

### Which is updated more often, iAttenuation or DOT Chart 17?

iAttenuation ships an update every 69 months, and DOT Chart 17 every 10 months. Most recently, iAttenuation was updated on October 5, 2026 and DOT Chart 17 on October 10, 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.*