# Compressor HP vs CalcEngineer

The clearest difference is in-app purchases: CalcEngineer at none against Compressor HP's 3. CalcEngineer also leads on update cadence (every 2 days vs every 4 months). Compressor HP's advantage is iOS requirement (14.4 vs 17). On price, ads and device support there is nothing between them.

Both are free to download. Compressor HP sells 3 one-off in-app purchases. CalcEngineer asks for nothing beyond the download.

Compressor HP ships an update every 4 months, CalcEngineer every 2 days. The most recent releases landed on October 6, 2026 and October 1, 2026 respectively.

## The numbers

| Metric | Compressor HP | CalcEngineer |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[5.0 (2 ratings)](https://appshunter.io/ios/app/calcengineer/id6748969344/reviews)** |
| Number of ratings | — | **2** |
| Positive reviews | — | 100.0% of reviews |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | Every 4 months | **Every 2 days** |
| Monetization | — | Free |
| Size | 3 MB | 10 MB |
| Requires iOS | **14.4** | 17 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 9+ |
| Developer | [Melchisedec Martinez Rodriguez](https://appshunter.io/developer/1534398511) | [Justin Bush](https://appshunter.io/developer/1828308327) |

## What reviewers say

### Compressor HP

[App page](https://appshunter.io/ios/app/compressor-hp/id1539320947)

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

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Unlock capacitor size | $0.99 | one-time |
| Unlock compressors type | $2.99 | one-time |
| Unlock all refrigerants | $2.99 | one-time |


### CalcEngineer

[App page](https://appshunter.io/ios/app/calcengineer/id6748969344)

This app provides professional engineering calculations for compressed air systems. It helps engineers and technicians determine CFM requirements, size compressors and tanks, and analyze pressure drops for optimized pneumatic systems.

**Highlights:** CFM Calculator, Compressor & Tank Sizing, Pressure Drop Analysis, Flow Velocity & Pipe Sizing, Multiple CFM Entries, General Engineering Calculator Suite

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is Compressor HP free?

Compressor HP is free to download, with in-app purchases available.

### Is CalcEngineer free?

CalcEngineer is free to download, with no in-app purchases.

### Do Compressor HP or CalcEngineer have ads?

Neither Compressor HP nor CalcEngineer shows ads.

### Which is updated more often, Compressor HP or CalcEngineer?

Compressor HP ships an update every 4 months, and CalcEngineer every 2 days. Most recently, Compressor HP was updated on October 6, 2026 and CalcEngineer on October 1, 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.*