Nautical Distance Calculator: Map & Measure Nautical Miles
Our free online nautical distance calculator helps you measure distances in nautical miles between any points on the globe. Whether you’re planning a sailing route, calculating fuel requirements, or studying marine navigation, this interactive tool provides accurate measurements using both great circle and rhumb line calculations.
Nautical Distance Calculator
- Great Circle Distance (shortest path)
- Rhumb Line Distance (constant bearing path)
- Initial and Final Bearings
| Point # | Coordinates (DMS) | Coordinates (Decimal) | Segment Distance | Actions |
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Key Features
- Calculate distances in nautical miles between multiple points
- View both great circle (shortest path) and rhumb line (constant bearing) distances
- Get initial and final bearings for each route segment
- Display coordinates in both decimal and DMS (degrees, minutes, seconds) formats
- Toggle between street map, satellite imagery, and marine navigation layers
- View bathymetry data and compass rose overlays for enhanced navigation planning
How to Use the Calculator
- Click points on the map to create your route
- Each segment will show:
- Great circle distance (shortest path) in nautical miles
- Rhumb line distance (constant bearing path) in nautical miles
- Initial and final bearings
- For multiple-point routes, you’ll see individual segment distances and total route distance
- Use the layer control to switch between map views and add marine navigation overlays
- Copy coordinates easily from the table below the map
Understanding the Measurements
Great Circle vs Rhumb Line
- Great Circle Distance: Shows the shortest path between two points on Earth’s surface, ideal for long-distance navigation
- Rhumb Line Distance: Follows a constant bearing, often easier to navigate but typically longer than great circle routes
Initial vs Final Bearings
On long routes, your initial bearing will differ from your final bearing due to Earth’s curvature. This is particularly noticeable on routes crossing multiple lines of longitude.
Common Uses
- Planning sailing routes and marine navigation
- Calculating fuel requirements for marine journeys
- Measuring distances between ports
- Educational purposes for marine navigation training
- General maritime route planning
Technical Limitations
- All distances are calculated assuming a spherical Earth
- Calculations don’t account for wind, currents, or other environmental factors
- The tool doesn’t consider land masses or navigation hazards
- Maximum zoom level is limited by the map service provider
- Bathymetry data may not be available for all areas
Tips for Accurate Measurements
- Zoom in for more precise point placement
- Use the satellite view for better reference near coastlines
- Check both great circle and rhumb line distances for route planning
- Consider breaking long routes into smaller segments for more detailed planning
- Refer to official nautical charts for actual navigation
Remember that while this nautical mile calculator is a useful planning tool, it should not be used as your primary navigation instrument. Always rely on proper marine navigation equipment and official nautical charts for actual navigation.
Need to measure a distance in nautical miles? Try our calculator above and let us know if you have any questions about measuring nautical distances on our interactive map.
Disclaimer: This tool is for planning and educational purposes only. Do not use for actual navigation without proper marine navigation equipment and charts.
