# Caleffi Pipe Sizer vs IndexOS

The clearest difference is in-app purchases: Caleffi Pipe Sizer at none against IndexOS's 2. Caleffi Pipe Sizer also leads on iOS requirement (13.0 vs 15.0). IndexOS's advantage is update cadence (every 4 weeks vs every 7 months). On price, ads and device support there is nothing between them.

Both are free to download. IndexOS sells 2 in-app purchases, starting at $3.99 per month. Caleffi Pipe Sizer asks for nothing beyond the download.

Caleffi Pipe Sizer ships an update every 7 months, IndexOS every 4 weeks. The most recent releases landed on October 2, 2026 and October 8, 2026 respectively.

## The numbers

| Metric | Caleffi Pipe Sizer | IndexOS |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[5.0 (1 ratings)](https://appshunter.io/ios/app/caleffi-pipe-sizer/id1088928458/reviews)** | — |
| Number of ratings | **1** | — |
| Positive reviews | 50.0% of reviews | — |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 7 months | **Every 4 weeks** |
| Monetization | Free | — |
| Size | 44 MB | 155 MB |
| Requires iOS | **13.0** | 15.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Caleffi S.p.A](https://appshunter.io/developer/920722440) | [Alessandro Silvio Celotto](https://appshunter.io/developer/6781339350) |

## What reviewers say

### Caleffi Pipe Sizer

[App page](https://appshunter.io/ios/app/caleffi-pipe-sizer/id1088928458)

This application assists hydraulic and HVAC professionals in accurately sizing water or air pipes. It calculates pressure drops and offers a modern, intuitive interface for precise system design on the go.

**Highlights:** Accurate water/air pipe sizing, Pressure drop calculation, Customizable technical parameter calculations, Extensive material and configuration library, Modern and intuitive interface, Enhanced performance

**Features:** macOS Compatibility

**In-app purchases:** none


### IndexOS

[App page](https://appshunter.io/ios/app/indexos/id6781729474)

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

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| IndexOS - Piano Mensile | $3.99 | per month |
| IndexOS - Piano Annuale | $44.99 | per year |


## Frequently asked questions

### Is Caleffi Pipe Sizer free?

Caleffi Pipe Sizer is free to download, with no in-app purchases.

### Is IndexOS free?

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

### Do Caleffi Pipe Sizer or IndexOS have ads?

Neither Caleffi Pipe Sizer nor IndexOS shows ads.

### Which is updated more often, Caleffi Pipe Sizer or IndexOS?

Caleffi Pipe Sizer ships an update every 7 months, and IndexOS every 4 weeks. Most recently, Caleffi Pipe Sizer was updated on October 2, 2026 and IndexOS on October 8, 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.*