Boating Calcs vs Propeller Calc
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Boating Calcs
This app offers over 120 boating calculations and unit conversions, along with 120 reference pages. Easily solve a variety of boating-related problems, save and share your calculations, and quickly find the tools you need. It includes extensive reference material across various boating disciplines.
- Over 120 boating calculations
- Extensive unit conversions
- 120+ reference pages
- Save and open calculations
- Add calculators to favorites
- Email calculation inputs and results
- Search functionality
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You asked for more calculators and we've added them. Boating Calcs has over 120 boating calculations and unit conversions and 120 reference pages. With Boating Calcs you can quickly and easily solve a variety of boating calculations from your iPhone or iPad. Not just calculators, but the ability save and open saved calculations and add calculators to a favorites list. You can also email calculator inputs and results so you can easily share your calculations. Search functionality enables you to quickly find the calculator you want. Chapters: * Area, Angles & Volume * Communications References * Unit Conversions * Finance Calculations * Fuel Calculations * Glossary / Acronyms * Line Calculations and References * Knot References * Mechanical & Electrical Calculations * Performance Calculations * Piloting Calculations * Propeller Reference and Calculations * Weather & Waves Reference and Calculations If there's a calculator or reference material you'd like to see added, visit our website and send us an email.
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
Screenshots
Verdict
The clearest difference is price: Propeller Calc at Free against Boating Calcs's $1.99. Propeller Calc also leads on review sentiment (100% vs 81%). Boating Calcs's advantage is rating (4.8 vs 3.0) and ratings volume (27 vs 1). On ads, in-app purchases, monetization model 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
Propeller Calc is free to download; Boating Calcs costs $1.99 up front. Neither carries in-app purchases, so what you see is what you pay.
Boating Calcs holds the better App Store score, 4.8 against 3.0. That said, the two scores are not equally well evidenced: Boating Calcs has 27 ratings behind it against 1, so its average is the more settled of the two. Written reviews complicate that: 81% of Boating Calcs's written reviews are positive against 100% of Propeller Calc's, so the app with the better star average is not the one people write more warmly about.
Boating Calcs ships an update every 7 months, Propeller Calc every 21 months. The most recent releases landed on October 15, 2026 and September 26, 2026 respectively.
| Parameter | Boating Calcs | Propeller Calc |
|---|---|---|
| Price | $1.99 | Free — better |
| Rating | 4.8 (27 ratings) — better | 3.0 (1 ratings) |
| Positive reviews | 81.3% of reviews | 100.0% of reviews — better |
| Number of ratings | 27 — better | 1 |
| Update frequency | Every 7 months — better | Every 21 months |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Free | Free |
| Devices | iPhone, iPad, iPod — better | iPhone, iPad |
| Requires iOS | 9.0 — better | 17.0 |
| Further details — not scored | ||
| Size | 17 MB | 3 MB |
| Age rating | 4+ | 4+ |
| Developer | Calculated Industries | Frode Rørvik |
Customer experience
Boating Calcs
Propeller Calc
In-app purchases
Boating Calcs
No in-app purchases
Propeller Calc
No in-app purchases
Questions
Is Boating Calcs free?
Is Propeller Calc free?
Which has better reviews, Boating Calcs or Propeller Calc?
Do Boating Calcs or Propeller Calc have ads?
Which is updated more often, Boating Calcs or Propeller Calc?
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