# Propeller Calc vs ASTM 54 B

The clearest difference is review sentiment: Propeller Calc at 100% against ASTM 54 B's 0%. Propeller Calc also leads on price (Free vs $9.99). ASTM 54 B's advantage is update cadence (every 6 months vs every 21 months). On ads, in-app purchases, device support and iOS requirement there is nothing between them.

Propeller Calc is free to download; ASTM 54 B costs $9.99 up front. Neither carries in-app purchases, so what you see is what you pay.

Propeller Calc ships an update every 21 months, ASTM 54 B every 6 months. The most recent releases landed on September 26, 2026 and October 24, 2026 respectively.

## The numbers

| Metric | Propeller Calc | ASTM 54 B |
| --- | --- | --- |
| Price | **Free** | $9.99 |
| Rating | **[3.0 (1 ratings)](https://appshunter.io/ios/app/propeller-calc/id478119478/reviews)** | — |
| Number of ratings | **1** | — |
| Positive reviews | **100.0% of reviews** | 0.0% of reviews |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 21 months | **Every 6 months** |
| Monetization | **Free** | Paid |
| Size | 3 MB | 1 MB |
| Requires iOS | **17.0** | 17.6 |
| Devices | **iPhone, iPad** | iPhone |
| Age rating | 4+ | 4+ |
| Developer | [Frode Rørvik](https://appshunter.io/developer/478119481) | [Oleksii Nezhalskyi](https://appshunter.io/developer/1687730603) |

## 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


### ASTM 54 B

[App page](https://appshunter.io/ios/app/astm-54-b/id6449903055)

This application calculates fuel weight for ships based on ASTM 54 B standards. Users input volume and observed temperature to receive precise calculations.

**Highlights:** ASTM 54 B fuel weight calculation, Input volume and temperature, Automatic calculation, User-friendly interface

**Features:** macOS Compatibility, 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 ASTM 54 B free?

ASTM 54 B costs $9.99, with no in-app purchases.

### Do Propeller Calc or ASTM 54 B have ads?

Neither Propeller Calc nor ASTM 54 B shows ads.

### Which is updated more often, Propeller Calc or ASTM 54 B?

Propeller Calc ships an update every 21 months, and ASTM 54 B every 6 months. Most recently, Propeller Calc was updated on September 26, 2026 and ASTM 54 B on October 24, 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.*