The words, before the math

Your METAR reports visibility in statute miles while your airspeed indicator reads knots. These two converters bridge the systems — and show the arithmetic instead of hiding it.

Knot (kt) — a speed: 1 nautical mile traveled in 1 hour. Never a distance.
Nautical mile (NM) — exactly 1,852 meters, close to one minute of latitude, which is why charts and navigation use it.
Statute mile (mi) — exactly 1,609.344 meters (5,280 ft), the everyday land mile of road signs and METAR visibility.
Conversion factor — 1,852 ÷ 1,609.344 = 1.150779448. One number converts both speed and distance, because a knot is just a nautical mile with a clock attached.

Knots and miles per hour

Converter 1 · speed · knots ⇆ miles per hour

Knots (kt)

Miles per hour (mph)

Decimals

One hour, two ways of counting it. Both aircraft fly the identical speed for exactly one hour and arrive at the identical point — the numbers differ because the top lane counts the distance in nautical miles and the bottom lane counts the same distance in statute miles. 1 knot means 1 nautical mile traveled in 1 hour — a knot is a speed, never a distance.

at 100 kt

–

at 115.078 mph

–

T+0 → T+60 min · same start, same finish

Nautical and statute miles

Converter 2 · distance · nautical ⇆ statute miles

Nautical miles (NM)

Statute miles (mi)

Decimals

See where the factor comes from

1 NM × (1,852 m / 1 NM) × (1 mi / 1,609.344 m) = 1.150779448 mi
1 mi × (1,609.344 m / 1 mi) × (1 NM / 1,852 m) = 0.868976242 NM

The struck-through units cancel: nautical miles to meters, meters to statute miles. Only the destination unit survives.

One route, two rulers. The route below has one physical length. The cyan ruler above it measures in nautical miles; the green ruler below measures in statute miles. Fewer nautical-mile ticks fit — each one is longer.

1 nautical mile · 1,852 m

1 statute mile · 1,609.344 m

← 242.656 m difference

A nautical mile is about 15.08% longer than a statute mile, so the same route has a larger numerical value when measured in statute miles.

Why these units differ

The nautical mile is built from the planet: one minute of latitude is very nearly 1,852 meters, so distances in nautical miles convert cleanly to angles on a chart — which is why aviation and marine navigation, groundspeeds, and winds aloft all use nautical miles and knots. The statute mile is built from land surveying: 5,280 feet, standardized in 1959 as exactly 1,609.344 meters, and it survives in aviation anywhere the ground rules — most notably METAR visibility.

Because both conversions divide the same two meter definitions, one factor serves both: multiply knots by 1.150779448 to get miles per hour, and multiply nautical miles by the same number to get statute miles. Going the other way divides by it (or multiplies by 0.868976242, the same thing).