How to Compare Air Miles to Land Miles

Planning trips by air or land both start with figuring out mileage.

Air and land travel both measure distances in miles. Distance is calculated in statute miles for land and nautical miles--the same measurement used on water--for air travel.

Statute/Land Miles

Statute (land) miles are equivalent to 1/3 of a league, or 8 furlongs, and are based on the foot in English speaking countries. Statute miles measure 5,280 feet. The U.S. statute mile is about 1/8 mile longer than the international statute mile, due to slight variations in foot measurements.

Aeronautical Miles

Aeronautical/nautical miles are based on one minute of arc at any of earth's latitudes, allowing for the earth's curvature. They're based on the earth's circumference of 360 degrees, divided into 60 minutes. Each degree equals one minute of arc, which is equal to 6,076 miles.

Course Plotting

Whether traveling by air or land, plotting a course includes charting or mapping out reference points, then calculating mileage. Travel time can then be calculated in miles per hour or knots.

Aeronautical/Statute Mile Conversion

One statute mile equals 0.86897624 nautical miles. One nautical mile (nm) is equivalent to 1.15077945 statute miles. One knot is the rate of 1 nautical miles per hour, so a speed of 30 knots is the same as 34.5 statute miles per hour.

References

• AirmilesMaps.com: Types of Mile.
• How Stuff Works: What Is A Nautical Mile, And How Does It Differ From A Normal Mile And A Kilometer?
• Aviation Flyers: Navigation.
• Math in Flight: Statute Miles Vs. Nautical Miles.
• Pilot Friend: Navigational Measurements.

Resources

• RGV. org: Miles Information.
• Aviation Speed and Distance Converter
• Measure for Measure. Richard A. Young and Thomas J. Glover.1996.
• BoatSafe.com: Conversion for Nautical and Statute Miles.
• Federal Aviation Administration: World Aeronautical Chart.