Propeller Calc vs MarinePro
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Propeller Calc
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.
- 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
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This calculator can determine pitch, gear ratio, RPM, propeller slip and speed parameters. Enter any four variables, and it will calculate the fifth. Use the toggle switch to choose which field to calculate. Pitch is the theoretical forward movement for one complete turn of the propeller. Every inch of the boat in contact with the water induces drag. Therefore, the distance travelled differs since the propeller is "slipping" behind the theoretical distance it should travel with each rotation. The difference between theory and reality is called slip. Depending on your application, slip typically ranges between 5% and 20%. A lower number is only sometimes what you are after. Slip of a prop changes with operating conditions and is not a direct measure of efficiency. Please consult professionals for guidance. Happy powerboating
MarinePro
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【MarinePro Introduction】 The intelligent AI designed exclusively for the maritime industry—MarinePro is the ultimate AI assistant tailored for maritime maintenance professionals! Featuring real-time fault diagnosis and intelligent repair solution recommendations, it simplifies complex equipment maintenance, making it "as easy as looking up a dictionary"! 【MarinePro Features】 1.Ship Database: Access a vast collection of equipment manuals and engineering case studies. 2.Favorites: Bookmark critical resources with one click and retrieve them anytime. 3.Share: Enable seamless knowledge sharing through one-click solution distribution. Official WeChat Account : 儒海之家 Official Email: newmkt@winkong.net
Screenshots
Verdict
The clearest difference is update cadence: MarinePro at every 2 months against Propeller Calc's every 21 months. MarinePro also leads on iOS requirement (13.0 vs 17.0). On price, ads, in-app purchases and device support there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
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, MarinePro every 2 months. The most recent releases landed on September 26, 2026 and October 28, 2026 respectively.
| Parameter | Propeller Calc | MarinePro |
|---|---|---|
| Price | Free | Free |
| Rating | 3.0 (1 ratings) — better | — |
| Positive reviews | 100.0% of reviews | — |
| Number of ratings | 1 — better | — |
| Update frequency | Every 21 months | Every 2 months — better |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Free | — |
| Devices | iPhone, iPad | iPhone, iPad, iPod — better |
| Requires iOS | 17.0 | 13.0 — better |
| Further details — not scored | ||
| Size | 3 MB | 12 MB |
| Age rating | 4+ | 4+ |
| Developer | Frode Rørvik | Winkong Marine Engineering Co.,Ltd. |
In-app purchases
Propeller Calc
No in-app purchases
MarinePro
No in-app purchases
Questions
Is Propeller Calc free?
Is MarinePro free?
Do Propeller Calc or MarinePro have ads?
Which is updated more often, Propeller Calc or MarinePro?
Other comparisons
