About the Nautical Miles Converter
This nautical miles converter changes a distance in nautical miles into statute (land) miles, kilometres, metres, feet and cables, and works in reverse too — enter miles or kilometres and get nautical miles. Add a cruising speed in knots to see how long the leg will take.
Nautical miles are the standard distance unit at sea and in the air, so the tool is handy for sailors planning a passage, pilots reading flight plans and charts, cruise passengers comparing itineraries, and students learning navigation. Because a knot is one nautical mile per hour, distance in nmi divided by speed in knots gives hours directly.
The international nautical mile is defined as exactly 1,852 metres, originally chosen to approximate one minute of latitude. It is about 15% longer than a statute mile (1,609.344 m), so 100 nmi is roughly 115 miles or 185 km.
With the default inputs, the converted distance is 185.2. Change any value above to recalculate instantly.
How to use the nautical miles converter
- 1Enter the distance.
- 2Pick the unit it is in (nautical miles, miles, km, metres, feet or cables).
- 3Pick the unit you want as the headline answer.
- 4Optionally enter your speed in knots to estimate passage time.
- 5Read the converted distance and the equivalents in every other unit.
Formula and method
Since 1929 the international nautical mile has been defined as exactly 1,852 metres, and the international statute mile as exactly 1,609.344 metres. The calculator converts your distance to metres, then divides by the size of the target unit, so every result is exact up to rounding.
One nautical mile equals 1.852 km or about 1.15078 statute miles; one statute mile is about 0.86898 nmi. A cable is one tenth of a nautical mile (185.2 m). Travel time is simply distance in nautical miles divided by speed in knots, because one knot is one nautical mile per hour; it ignores current, wind and tacking.
- nmi
- Distance in international nautical miles
- mi
- Distance in statute (land) miles
- knots
- Speed in nautical miles per hour
Worked examples
100 nautical miles to kilometres
100 × 1,852 m = 185,200 m = 185.2 km, or 185,200 ÷ 1,609.344 = 115.08 statute miles. At 6 knots the passage takes 100 ÷ 6 ≈ 16.7 hours.
Marathon distance in nautical miles
26.2 miles × 1,609.344 = 42,164.8 m. Divided by 1,852 m per nautical mile, that is 22.77 nmi.
500 km flight leg
500,000 m ÷ 1,852 = 269.98 nmi. At a ground speed of 250 knots the leg takes 269.98 ÷ 250 ≈ 1.08 hours (about 65 minutes).
Frequently asked questions
How many miles is a nautical mile?+
One nautical mile is about 1.15078 statute miles (exactly 1,852 m ÷ 1,609.344 m). Multiply nautical miles by 1.15 for a quick estimate.
How many kilometres is a nautical mile?+
Exactly 1.852 km. The international nautical mile was defined as 1,852 metres in 1929 and adopted by the US and UK in 1954 and 1970 respectively.
Why do ships and planes use nautical miles?+
A nautical mile is approximately one minute of latitude, so distances can be measured straight off a chart’s latitude scale. Speeds in knots (nmi per hour) then combine neatly with chart distances.
What is the difference between a knot and a nautical mile?+
A nautical mile is a distance (1,852 m); a knot is a speed of one nautical mile per hour, which is 1.852 km/h or about 1.15 mph.
What is the abbreviation for nautical mile?+
The common abbreviations are nmi, NM and nm. Aviation typically writes NM; "nm" can be confused with nanometre, so nmi is the least ambiguous.