Sextant Calculator
Navigation
Only for iPhone
$1.00 · Designed for iPhone. Not verified for macOS.
iPhone
Sextant Calculator is the essential tool for celestial navigators, designed to simplify the arithmetic of sight reductions.
FEATURES
- Angle Calculations
Enter angles in degrees and decimal minutes (DD° MM.m') format. Add, subtract, or divide angles with a single tap. Perfect for working through sun, star, and planet sights.
- Time Calculations
Work with hours, minutes, and seconds. Add and subtract times for GMT calculations, zone time conversions, and chronometer checks. Results automatically handle overflow into days when needed.
- Averaging Made Simple
Use the divide function to quickly calculate the average of multiple sights. Enter your total, divide by the number of observations, and get your mean position.
- Purpose-Built Keypad
A custom colour-coded keypad designed specifically for navigation calculations. No fumbling with a standard calculator - every button has a purpose.
- Day and Night Modes
Switch to red night mode to preserve your dark adaptation during night watches. Essential for practical celestial navigation at sea.
- Results Tape
See your complete calculation history in the scrollable results display. Review your work and catch errors before they affect your position.
DESIGNED FOR NAVIGATORS
Whether you're a yacht skipper crossing an ocean, a merchant marine officer maintaining traditional skills, or a student learning celestial navigation, Sextant Calculator removes the tedium from sight reduction arithmetic.
No more mental arithmetic errors. No more reaching for pencil and paper. Just clean, accurate calculations every time.
Works offline - no internet connection required. Your navigation calculations work wherever you are, from mid-ocean to the most remote anchorage.
Ratings & Reviews
- This app hasn’t received enough ratings or reviews to display an overview.
- Added developer website link
The developer, Will Downing, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Not Collected
The developer does not collect any data from this app.
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- Will Downing
- Size
- 2.4 MB
- Category
- Navigation
- Compatibility
Requires iOS 15.0 or later.
- iPhone
Requires iOS 15.0 or later. - iPod touch
Requires iOS 15.0 or later. - Mac
Requires macOS 12.0 or later and a Mac with Apple M1 chip or later. - Apple Vision
Requires visionOS 1.0 or later.
- iPhone
- Languages
- English
- Age Rating
4+
- 4+
- Copyright
- © 2025 MBP
