# Propeller Calc vs SpeedLink Competition

The clearest difference is iOS requirement: SpeedLink Competition at 11.0 against Propeller Calc's 17.0. On price, update cadence, ads and in-app purchases there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

Propeller Calc ships an update every 21 months, SpeedLink Competition every 12 months. The most recent releases landed on September 9, 2026 and September 12, 2026 respectively.

## The numbers

| Metric | Propeller Calc | SpeedLink Competition |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[3.0 (1 ratings)](https://appshunter.io/ios/app/propeller-calc/id478119478/reviews)** | — |
| Number of ratings | **1** | — |
| Positive reviews | 100.0% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 21 months | **Every 12 months** |
| Monetization | Free | — |
| Size | 3 MB | 153 MB |
| Requires iOS | 17.0 | **11.0** |
| Devices | iPhone, iPad | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Frode Rørvik](https://appshunter.io/developer/478119481) | [Mercury Marine LLC](https://appshunter.io/developer/1777822540) |

## What reviewers say

### Propeller Calc

[App page](https://appshunter.io/ios/app/propeller-calc/id478119478)

This utility calculates propeller performance metrics like pitch, gear ratio, RPM, slip, and speed. Input any four values, and the app computes the fifth, helping users understand the relationship between propeller design and boat performance.

**Highlights:** Calculate pitch, gear ratio, RPM, slip, and speed, Enter any four variables to find the fifth, Understand propeller slip and its impact, Supports iPhone and iPad, Free to use

**Features:** macOS Compatibility

**In-app purchases:** none


### SpeedLink Competition

[App page](https://appshunter.io/ios/app/speedlink-competition/id1585408058)

**Features:** Vision Pro support

**In-app purchases:** none


## Frequently asked questions

### Is Propeller Calc free?

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

### Is SpeedLink Competition free?

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

### Do Propeller Calc or SpeedLink Competition have ads?

Neither Propeller Calc nor SpeedLink Competition shows ads.

### Which is updated more often, Propeller Calc or SpeedLink Competition?

Propeller Calc ships an update every 21 months, and SpeedLink Competition every 12 months. Most recently, Propeller Calc was updated on September 9, 2026 and SpeedLink Competition on September 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.*