About the Nautical Mile
A nautical mile is the standard distance unit for marine and air navigation. This calculator converts a distance you enter — in nautical miles, statute miles, kilometers, meters, feet, or yards — into nautical miles, statute miles, and kilometers, and also works out how long that distance takes to cover at a given speed in knots.
The formula
The international nautical mile was fixed in 1929 at exactly 1,852 meters. Every other unit conversion follows from that anchor and the exact meter equivalents of the other units:
- 1 nautical mile (nm) = 1,852 meters exactly
- 1 statute mile (mi) = 1,609.344 meters exactly (5,280 feet)
- 1 kilometer (km) = 1,000 meters
- 1 foot (ft) = 0.3048 meters exactly
- 1 yard (yd) = 0.9144 meters exactly
To convert, the calculator first turns your entered distance into meters using the exact factor for the unit you chose, then divides that meter value by 1,852 (for nautical miles), by 1,609.344 (for statute miles), or by 1,000 (for kilometers). So 1 nautical mile ≈ 1.15078 statute miles ≈ 1.852 kilometers ≈ 6,076.12 feet.
Knots and travel time
A knot is a unit of speed equal to one nautical mile per hour — it already includes "per hour," so "knots per hour" is not a real unit. Travel time follows the standard distance/speed relationship:
Time (hours) = Distance (nautical miles) ÷ Speed (knots)
The calculator converts your entered distance to nautical miles first, then divides by the speed you entered in knots to report the time. For example, 120 nautical miles at 15 knots takes 120 ÷ 15 = 8 hours.
Why the nautical mile is 1,852 meters
Unlike the statute mile, which is a fixed land-survey unit, the nautical mile is tied to the size of the Earth: 1,852 meters closely approximates the average length of one minute of latitude along a meridian. That link means a distance measured in nautical miles corresponds directly to an angular distance on a nautical chart, which is why mariners and pilots use it instead of statute miles or kilometers.