# Viscosity Conversion vs Fluid Mechanics Calc

The clearest difference is price: Fluid Mechanics Calc at Free against Viscosity Conversion's $2.99. Viscosity Conversion's advantage is iOS requirement (13 vs 15.6). On update cadence, ads, in-app purchases and device support there is nothing between them.

Fluid Mechanics Calc is free to download; Viscosity Conversion costs $2.99 up front. Neither carries in-app purchases, so what you see is what you pay.

Viscosity Conversion ships an update every 30 months, Fluid Mechanics Calc every 22 months. The most recent releases landed on October 29, 2026 and October 12, 2026 respectively.

## The numbers

| Metric | Viscosity Conversion | Fluid Mechanics Calc |
| --- | --- | --- |
| Price | $2.99 | **Free** |
| Rating | — | **[5.0 (3 ratings)](https://appshunter.io/ios/app/fluid-mechanics-calc/id1404879538/reviews)** |
| Number of ratings | — | **3** |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 30 months | **Every 22 months** |
| Monetization | — | Free |
| Size | 1 MB | 108 MB |
| Requires iOS | **13** | 15.6 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Nitrio](https://appshunter.io/developer/321121189) | [Trelleborg Sealing Solutions](https://appshunter.io/developer/396863758) |

## What reviewers say

### Viscosity Conversion

[App page](https://appshunter.io/ios/app/viscosity-conversion/id630288155)

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

**In-app purchases:** none


### Fluid Mechanics Calc

[App page](https://appshunter.io/ios/app/fluid-mechanics-calc/id1404879538)

This utility app provides a comprehensive calculator for fluid mechanics, civil, and structural engineering parameters. It offers over 130 formulas and 360 calculation methods, supporting seamless unit system switching for analysis, design, and operation of fluid-related systems.

**Highlights:** 130+ fluid mechanics formulas, 360+ calculation methods, Unit system conversion (metric/US), Favorite formula marking, High mathematical precision, Seamless unit switching

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is Viscosity Conversion free?

Viscosity Conversion costs $2.99, with no in-app purchases.

### Is Fluid Mechanics Calc free?

Fluid Mechanics Calc is free to download, with no in-app purchases.

### Do Viscosity Conversion or Fluid Mechanics Calc have ads?

Neither Viscosity Conversion nor Fluid Mechanics Calc shows ads.

### Which is updated more often, Viscosity Conversion or Fluid Mechanics Calc?

Viscosity Conversion ships an update every 30 months, and Fluid Mechanics Calc every 22 months. Most recently, Viscosity Conversion was updated on October 29, 2026 and Fluid Mechanics Calc on October 12, 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.*