# Air Density Calculator vs Transformer Calculation Tool

The clearest difference is price: Transformer Calculation Tool at Free against Air Density Calculator's $2.99. Transformer Calculation Tool also leads on update cadence (every 4 weeks vs every 20 months) and iOS requirement (13.0 vs 17.6). Air Density Calculator's advantage is in-app purchases (none vs 1). On ads and device support there is nothing between them.

Transformer Calculation Tool is free to download; Air Density Calculator costs $2.99 up front. Transformer Calculation Tool sells 1 one-off in-app purchase. Air Density Calculator asks for nothing beyond the download.

Air Density Calculator ships an update every 20 months, Transformer Calculation Tool every 4 weeks. The most recent releases landed on September 22, 2026 and September 16, 2026 respectively.

## The numbers

| Metric | Air Density Calculator | Transformer Calculation Tool |
| --- | --- | --- |
| Price | $2.99 | **Free** |
| Rating | **[5.0 (2 ratings)](https://appshunter.io/ios/app/air-density-calculator/id1421668162/reviews)** | — |
| Number of ratings | **2** | — |
| Positive reviews | 100.0% of reviews | — |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 20 months | **Every 4 weeks** |
| Monetization | Paid | — |
| Size | 1 MB | 57 MB |
| Requires iOS | 17.6 | **13.0** |
| Devices | iPhone, iPad | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [Nitrio](https://appshunter.io/developer/321121189) | [Shraddhaben Parmar](https://appshunter.io/developer/1889769325) |

## What reviewers say

### Air Density Calculator

[App page](https://appshunter.io/ios/app/air-density-calculator/id1421668162)

Instantly calculate air density and atmospheric properties with this offline engineering tool. Features three modes for density, reverse solving, and altitude estimation, with flexible unit support and calculation breakdown.

**Highlights:** Accurate air density calculation, Density, Reverse Solve, and Altitude modes, Flexible unit support, Show calculation steps, Tap to copy results, Calculation history, Offline functionality

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

**In-app purchases:** none


### Transformer Calculation Tool

[App page](https://appshunter.io/ios/app/transformer-calculation-tool/id6772152007)

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Lifetime premium | $9.99 | one-time |


## Frequently asked questions

### Is Air Density Calculator free?

Air Density Calculator costs $2.99, with no in-app purchases.

### Is Transformer Calculation Tool free?

Transformer Calculation Tool is free to download, with in-app purchases available.

### Do Air Density Calculator or Transformer Calculation Tool have ads?

Neither Air Density Calculator nor Transformer Calculation Tool shows ads.

### Which is updated more often, Air Density Calculator or Transformer Calculation Tool?

Air Density Calculator ships an update every 20 months, and Transformer Calculation Tool every 4 weeks. Most recently, Air Density Calculator was updated on September 22, 2026 and Transformer Calculation Tool on September 16, 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.*