# Bellows Design Software vs NPSH Calculator

The clearest difference is price: Bellows Design Software at Free against NPSH Calculator's $1.99. Bellows Design Software also leads on update cadence (monthly vs every 4 months). On ads, in-app purchases, device support and iOS requirement there is nothing between them.

Bellows Design Software is free to download; NPSH Calculator costs $1.99 up front. Bellows Design Software sells 2 in-app purchases, starting at $34.99 per month and NPSH Calculator sells 1 one-off in-app purchase. Whichever you choose, the download price is not the number that matters.

Bellows Design Software ships an update monthly, NPSH Calculator every 4 months. The most recent releases landed on September 15, 2026 and September 14, 2026 respectively.

## The numbers

| Metric | Bellows Design Software | NPSH Calculator |
| --- | --- | --- |
| Price | **Free** | $1.99 |
| Rating | **[5.0 (1 ratings)](https://appshunter.io/ios/app/bellows-design-software/id1635945221/reviews)** | — |
| Number of ratings | **1** | — |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | **Monthly** | Every 4 months |
| Monetization | Free with in-app purchases | — |
| Size | 26 MB | 34 MB |
| Requires iOS | 16.0 | **15.1** |
| Devices | iPhone, iPad, Mac | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [V PUGAZHENTHI](https://appshunter.io/developer/491898049) | [Transparent Blue Water LLC](https://appshunter.io/developer/1847968351) |

## What reviewers say

### Bellows Design Software

[App page](https://appshunter.io/ios/app/bellows-design-software/id1635945221)

This application assists in designing metallic bellows type expansion joints according to EJMA Standards. It allows users to input various design parameters and movement inputs to ensure safe and reliable usage. The software performs comprehensive calculations and checks against EJMA conditions for different bellows configurations and materials.

**Highlights:** Design metallic bellows expansion joints, Input internal diameter, convolution height, ply thickness, pitch, and number of plies, Set design pressure, temperature, and movements, Check design parameters against EJMA Standards, Calculations for single and dual bellows, Includes vibration and bellows forming methods, Calculations for tie rods, lugs plate, and hinges

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| All Access for Bellows | $34.99 | per month |
| All Access for Bellows Design | $299.99 | per year |


### NPSH Calculator

[App page](https://appshunter.io/ios/app/npsh-calculator/id6756281499)

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| NPSH Industrial | $4.99 | one-time |


## Frequently asked questions

### Is Bellows Design Software free?

Bellows Design Software is free to download, with in-app purchases available.

### Is NPSH Calculator free?

NPSH Calculator costs $1.99, and also offers in-app purchases.

### Do Bellows Design Software or NPSH Calculator have ads?

Neither Bellows Design Software nor NPSH Calculator shows ads.

### Which is updated more often, Bellows Design Software or NPSH Calculator?

Bellows Design Software ships an update monthly, and NPSH Calculator every 4 months. Most recently, Bellows Design Software was updated on September 15, 2026 and NPSH Calculator on September 14, 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.*