Conversions
Nautical Mile Converter
Convert nautical miles to statute miles, kilometers, meters, yards, and feet. Switch to speed mode for knots, mph, km/h, m/s, and ft/s.
Convert
100 nautical miles converted to every supported unit:
Nautical miles
100 nm
Statute miles
115.0779 mi
Kilometers
185.2 km
Meters
185,200 m
Yards
202,537.18 yd
Feet
607,611.55 ft
Nautical miles are used in aviation, maritime navigation, and meteorology. One nautical mile equals one minute of arc along a meridian, which is the historical definition that ties the unit to Earth's geometry.
Frequently Asked Questions about the Nautical Mile Converter
What is the difference between a nautical mile and a statute mile?
A nautical mile is 1,852 meters (about 1.15 statute miles), while a statute mile is 1,609.344 meters. The nautical mile is tied to Earth's geometry: one nautical mile corresponds to one minute of latitude along a meridian. The statute mile is a Roman-era land unit unrelated to navigation, so it is shorter and the two should not be used interchangeably on charts.
Why is 1 nautical mile exactly 1,852 meters?
The 1929 First International Extraordinary Hydrographic Conference in Monaco standardized the nautical mile at 1,852 meters exactly. Before then, the US used 1,853.248 m and the UK used 1,853.184 m. The US adopted the international value in 1954 and the UK in 1970, so today every chart, GPS unit, and navigation system uses the same 1,852 m definition.
What is a knot and how does it relate to nautical miles?
A knot is one nautical mile per hour, so 1 knot equals 1.852 km/h exactly and about 1.15077945 mph. The name comes from the 16th-century practice of measuring ship speed with a knotted rope let out behind the vessel for 30 seconds. Speed in knots is the standard unit in aviation and maritime navigation because it relates directly to chart distances and latitude.
Where are knots still used today?
Knots remain the standard speed unit for pilots (airspeed and ground speed in cockpits worldwide), for maritime navigation (ship speed, currents, tidal flows), and for weather services reporting wind speed, especially in storm and hurricane bulletins. ICAO and IMO regulations both mandate knots for international aviation and shipping, which is why the unit has not been displaced by km/h or mph.
How can I estimate knots in my head?
For mph, multiply knots by 1.15 (or add about 15 percent), so 20 knots is roughly 23 mph. For km/h, multiply knots by 1.85 (or roughly double and subtract a bit), so 20 knots is roughly 37 km/h. The exact factor is 1.852, so doubling is accurate to within 8 percent, which is close enough for back-of-the-envelope weather and travel math.