Nautical Distance Converter
Nautical miles, knots context, km, miles, meters, feet with the 1852 m factor.
What it does
Sea and air navigation measure in minutes of latitude. One nautical mile is one minute of arc on a meridian, fixed since 1929 at exactly 1852 meters. Knots then read speed directly: one knot is one nautical mile per hour.
The tool above converts between nautical miles, kilometers, statute miles, meters, and feet. Pick source and target, enter the value, and read the answer with all five equivalents below it. Defaults of 10 nautical miles to kilometers open solved at 18.52 km.
The fixed 1852 anchors everything. A statute mile is 1609.344 m, so each nautical mile runs about 1.15078 land miles; a 100 mile hop at sea is 115 land miles. Pilots and sailors keep both because charts graduate in minutes while road signs do not.
Knots deserve one careful sentence: they are already per hour, so knots per hour is nonsense the way miles per hour per hour would be. A 10 mile leg at 10 knots takes one hour, and the same leg at 5 knots takes two.
Use the table for the core pairs, then convert freely. Round once at the end and keep land miles out of marine math.
How to use
- Enter the value in the source unit.
- Pick the source unit on the left and the target on the right.
- Read the converted line, then scan all units.
- Divide hours into distance for knot speeds.
- Round once at the end.
Formula
- 1852
- Meters in one nautical mile, exact by 1929 agreement.
- 1609.344
- Meters in one statute mile, exact.
- meters first
- Single hub so all pairs need one path.
Factors in meters: nmi 1852 (exact), km 1000, mile 1609.344, m 1, ft 0.3048. One knot equals one nautical mile per hour. Going through meters keeps one path for all pairs.
Worked example
Example: 10 nautical miles to kilometers
Value 10, from nautical miles, to kilometers.
- Meters first: 10 x 1852 = 18520 m.
- Divide by the target factor: 18520 / 1000 = 18.52 km.
- Result: 10 nmi = 18.52 km.
- Check back: 18.52 x 1000 / 1852 = 10 nmi.
- At 10 knots this leg takes exactly one hour.
Reference table
| Pair | Factor | Check |
|---|---|---|
| 1 nmi to m | 1852 (exact) | 10 nmi is 18520 m |
| 1 nmi to km | 1.852 | 10 nmi is 18.52 km |
| 1 nmi to land miles | 1.15078 | 100 nmi is 115.0779 mi |
| 1 knot | 1 nmi per hour | 10 nmi at 10 knots is 1 h |
Limits
- Distance only; speed needs time input.
- Spherical minutes vary slightly with latitude; 1852 is conventional.
- Statute survey miles on old deeds differ slightly.
- Flight levels use feet regardless.
Common mistakes
- Saying knots per hour.
- Using land miles on charts.
- Rounding 1852 to 1800 for real legs.
- Converting mid chain instead of once.
- Reading cables as miles (1 nmi is 10 cables).
Try it yourself
Quick checks. Answers sit tucked under each question.
20 km in nautical miles?
20000 / 1852 = 10.7991 nmi.
1 land mile in nautical miles?
1609.344 / 1852 = 0.869 nmi.
Time for 10 nmi at 20 knots?
10 nmi at 10 knots takes 1 hour; at 20 knots it takes half an hour.
Questions
How long is a nautical mile?
Exactly 1852 m, set in 1929 and used worldwide. Older US and UK miles differed slightly until both adopted it.
What is a knot?
Speed: one nautical mile per hour. Distance is nautical miles; speed is knots, never knots per hour.
Nautical miles to land miles?
About 1.15078. A 100 nmi leg is 115.1 statute miles.
Why do sailors love it?
One minute of latitude along a meridian. That is why charts graduate latitude in miles directly.
Does the page do kilometers to nmi?
Yes, by the same 1852 route: 20 km is 20000 m, divided by 1852 gives 10.7991 nmi.
What lists below the answer?
All five equivalents in meters, kilometers, miles, feet, and nmi, so one entry converts everywhere at once.