Comparison

Nautical Calculator vs EZ Celestial Navigation

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

Nautical Calculator

This app provides a comprehensive suite of tools for marine navigation, including celestial, distance, and conversion calculators. It offers over 35 nautical calculations and reference materials, including "The American Practical Navigator."

Highlights
  • Celestial Navigation Calculators
  • Conversions Calculators
  • Distance Calculators
  • Log and Trig Calculators
  • Sailings Calculators
  • Weather Data Calculators
  • Reference Documents
Features
Read full description

Nautical Calculator is an easy to use app to help solve the equations and conversions typically associated with marine navigation and includes celestial calculators, conversions calculators, distance calculators, logarithm and trigonometry calculators, and sailings calculators. This app is the finest nautical calculator you will find for the Apple iPhone, iPad, and iPod Touch and includes the computations, tables, and full text of the "The American Practical Navigator" by Nathaniel Bowditch. With more than 35 nautical calculations, unit conversions and reference material, we are sure you will find this app convenient in solving the planning and navigating problems associated with marine navigation. Calculations Include: Celestial Navigation Calculators ------------------------------------------------ 1. Compass Error from Amplitudes Observed on the Visible Horizon 2. Altitude Correction for Air Temperature 3. Table of Offsets 4. Latitude and Longitude Factors 5. Altitude Correction for Atmospheric Pressure 6. Altitude Factors & Change of Altitude 7. Pub 229 8. Compass Error from Amplitudes Observed on the Celestial Horizon 9. Meridian Angle and Altitude of a Body on the Prime Vertical Circle Conversions Calculators ------------------------------------------------ 1. Chart Scales and Conversion for Nautical and Statute Miles 2. Conversion for Meters, Feet and Fathoms Distance Calculators ------------------------------------------------ 1. Length of a Degree of Latitude and Longitude 2. Speed for Measured Mile and Speed, Time, and Distance 3. Distance of an Object by Two Bearings 4. Distance of the Horizon 5. Distance by Vertical Angle Measured Between Sea Horizon and Top of Object Beyond Sea Horizon 6. Traverse Table 7. Geographic Range 8. Distance by Vertical Angle Measured Between Waterline at Object and Top of Object 9. Dip of Sea Short of the Horizon 10. Distance by Vertical Angle Measured Between Waterline at Object and Sea Horizon Beyond Object 11. Meridional Parts Log and Trig Calculators ------------------------------------------------ 1. Log10 2. tangent 3. cosecant 4. sine 5. cotangent 6. cosine 7. secant Sailings Calculators ------------------------------------------------ 1. Great Circle Sailing 2. Mercator Sailing Time Zones Calculators ------------------------------------------------ 1. Time Zones 2. Zone Descriptions, and Suffixes Weather Data Calculators ------------------------------------------------ 1. Direction and Speed of True Wind 2. Correction of Barometer Reading for Height Above Sea Level 3. Correction of Barometer Reading for Gravity 4. Temperature Conversions 5. Relative Humidity and Dew Point 6. Correction of Barometer Reading for Temperature 7. Barometer Measurement Conversions Included Reference Documents ------------------------------------------------ 1. AMERICAN PRACTICAL NAVIGATOR - VOL 1 2. AMERICAN PRACTICAL NAVIGATOR - VOL 2 3. SIGHT REDUCTION TABLES VOL 1 0° - 15° 4. SIGHT REDUCTION TABLES VOL 2 15° - 30° 5. SIGHT REDUCTION TABLES VOL 3 30° - 45° 6. SIGHT REDUCTION TABLES VOL 4 45°- 60° 7. SIGHT REDUCTION TABLES VOL 5 60°- 75° 8. SIGHT REDUCTION TABLES VOL 6 75°- 90° Learn more at http://www.NauticalCalculator.com

About

EZ Celestial Navigation

This app simplifies celestial navigation using a sextant, providing tools to calculate your position at sea. It offers automated calculations or manual table access, with features for observation archiving and compass checks. Ideal for learning and practicing traditional navigation methods.

Highlights
  • Automated sight reduction and LOP plotting
  • Manual Nautical Almanac and Pub. 229 table access
  • Observation archiving and restoration
  • Compass check functionality
  • Printable Nautical Almanac pages and reports
  • Universal app for iOS and macOS
Features
Currently charting
Read full description

Celestial navigation has never been easier! With ezAlmanacOne and a sextant you will be finding your fix like a pro in no time! ezAlmanacOne is an evolution of the iPad version of ezAlmanac with the modern user interface used in the Windows 10 version of ezAlmanac. All of the features of ezAlmanac plus new features including: - Universal app runs on iPad, iPhone, iPod touch, and the new MacBook with M1 processor. - Supports all device orientations. All screens support zoom and pan. - Make bearing observations to perform compass checks. - Archive saved observations and restore observation data from an archive. - Includes quick start guide, usage examples, and other documentation to learn celestial navigation. - Print/Output Nautical Almanac pages, observation reports, and other app documentation. ezAlmanacOne will help you perform celestial navigation exactly as it has been done for hundreds of years. It produces all Nautical Almanac (1960-2059) and Pub. 229 tables exactly as you are used to seeing them in the printed form. All tables can be accessed directly for manual usage if you choose to do so. Since they are produced by the software they support zooming and panning, and you can highlight in the tables to easily find the correct value to use. Most users, however, will prefer to let ezAlmanacOne do all of the work. Simply enter the basic sight parameters, make and enter your observations, and ezAlmanacOne will do the rest. It performs all of the steps to correct your observation, find GP of the object, do the sight reduction, and plot the LOP. No steps are skipped and all details are shown. Click where the LOPs cross in the plot and you have found your fix! Besides finding your fix, ezAlmanacOne is one of the best tools available to perform compass checks from a bearing observation of one of the navigational bodies. The compass check function supports checking up to 5 devices from a single bearing observation. ezAlmanacOne will also create a report of your compass check that can be saved as a PDF file or printed for the ships records. Celestial navigation instructors love ezAlmanacOne because it does celestial navigation exactly as they teach it. Values obtained from the Nautical Almanac and Pub. 229 are clearly identified with an icon of the book. When you press the book icon you are taken to the page that has that value with the row, column and value highlighted. Even when ezAlmanacOne is doing all the work, it can teach you how to do it manually using the books. For manual celestial navigation you can generate and print Nautical Almanac pages to use as a backup on a passage. You can even print the sight reduction forms and plotting sheets you will need. ezAlmanacOne performs all astronomical calculations using the NOVAS 3.1 software from the US Naval Observatory (USNO) and a JPL ephemeris that covers the years 1960 through 2059. It also implements WMM-2020, the latest World Magnetic Model software available from NOAA, to compute magnetic declination. Since all calculations are performed in the software, ezAlmanacOne is fully functional with no dependency on the internet.

Screenshots

Nautical Calculator4 screens
EZ Celestial Navigation4 screens

Verdict

The call

The clearest difference is price: Nautical Calculator at $8.99 against EZ Celestial Navigation's $29.99. Nautical Calculator also leads on iOS requirement (9.1 vs 13.0). EZ Celestial Navigation's advantage is update cadence (monthly vs every 9 months) and chart position (#159 vs unranked). On rating, ads, in-app purchases and monetization model 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

CostPrice · In-app purchases · Ads · Monetization

Nautical Calculator costs $8.99 and EZ Celestial Navigation $29.99 up front. Neither carries in-app purchases, so what you see is what you pay.

ReceptionRating · Positive reviews · Number of ratings

On the App Store both sit at effectively the same score — 5.0 for Nautical Calculator against 4.9 for EZ Celestial Navigation. That said, the two scores are not equally well evidenced: EZ Celestial Navigation has 26 ratings behind it against 4, so its average is the more settled of the two.

UpkeepUpdate frequency

Nautical Calculator ships an update every 9 months, EZ Celestial Navigation monthly. Both last shipped on October 24, 2026.

Scorecard5 real differences · 6 level
Nautical Calculator versus EZ Celestial Navigation: the parameters behind the verdict, then further details
ParameterNautical CalculatorEZ Celestial Navigation
Price$8.99 — better$29.99
Rating5.0 (4 ratings) — better4.9 (26 ratings)
Positive reviews—100.0% of reviews
Number of ratings426 — better
Update frequencyEvery 9 monthsMonthly — better
AdsNoNo
In-app purchasesNoNo
MonetizationPaidPaid
Best chart rank—#159 — better
DevicesiPhone, iPad, iPodiPhone, iPad, iPod
Requires iOS9.1 — better13.0
Further details — not scored
Size11 MB153 MB
Age rating4+4+
DeveloperAviation Mobile Apps, LLC.EZ Celestial LLC

Customer experience

Nautical Calculator

All ratings4 ratings
Positive100.0%
Neutral0.0%
Negative0.0%

EZ Celestial Navigation

All ratings26 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews4 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

In-app purchases

None

Nautical Calculator

No in-app purchases

None

EZ Celestial Navigation

No in-app purchases

Questions

Is Nautical Calculator free?
Nautical Calculator costs $8.99, with no in-app purchases.
Is EZ Celestial Navigation free?
EZ Celestial Navigation costs $29.99, with no in-app purchases.
Which has better reviews, Nautical Calculator or EZ Celestial Navigation?
Nautical Calculator is rated higher. Nautical Calculator averages 5.0 out of 5 from 4 ratings, while EZ Celestial Navigation averages 4.9 from 26 ratings.
Do Nautical Calculator or EZ Celestial Navigation have ads?
Neither Nautical Calculator nor EZ Celestial Navigation shows ads.
Which is updated more often, Nautical Calculator or EZ Celestial Navigation?
Nautical Calculator ships an update every 9 months, and EZ Celestial Navigation monthly. Most recently, Nautical Calculator was updated on October 24, 2026 and EZ Celestial Navigation on October 24, 2026.

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