Knots to MPH Converter

Knots to mph and km/h

Type a speed and choose its unit: the converter shows it in knots, miles per hour, kilometers per hour and meters per second at once. It starts at 100 knots, which is 115.1 mph and 185.2 km/h.

A knot is a speed of one nautical mile per hour. The international nautical mile is exactly 1,852 meters, a length set in 1929 by what is now the International Hydrographic Organization and adopted by the United States in 1954. A statute mile, the mile on road signs, is exactly 1,609.344 meters. Everything else follows from those two numbers:

• 1 knot = 1.852 km/h, exactly
• 1 knot = 1.15078 mph
• 1 mph = 0.86898 knots
• 1 knot = 0.514444 meters per second

Common speeds

Knots to mph chart

Every whole knot from 1 to 50, for wind and boat speeds. Miles per hour are knots × 1,852 ÷ 1,609.344 and kilometers per hour are knots × 1.852, both rounded to two decimals. For faster speeds, use the table above or the converter.

Quick conversions in your head

• Knots to mph: add 15%. 120 knots is about 138 mph.
• Mph to knots: take off 13%. 150 mph is about 130 knots.
• Knots to km/h: multiply by 1.85, or double and take off 7.5%. 140 knots is about 259 km/h.
• Knots to nautical miles a minute: divide by 60. At 120 knots you cover 2 nautical miles every minute, the basis of most time and distance arithmetic in the cockpit; the ground speed calculator does the full problem.

The 15% rule is close enough for a mental check: it is off by less than a tenth of a percent.

On the E6B

A flight computer converts with the NAUT, STAT and KM arrows on its calculator side: put the value under the NAUT arrow and read the same speed under STAT for miles per hour and under KM for kilometers per hour. The arrows work for distances in the same way, since a speed in knots is just nautical miles per hour. The E6B simulator has the same arrows to practice on.

Where knots show up in flying

Airspeeds, ground speeds and winds are given in knots. In a METAR, 27015G25KT is a wind from 270 degrees at 15 knots gusting to 25, and the METAR decoder spells out every group. Distances on charts and in flight plans are in nautical miles, which keeps speed and distance in step: at 100 knots, 100 nautical miles take an hour. In the United States, though, visibility in a METAR is in statute miles, the one place a land mile turns up in a weather report. For distances, the nautical miles converter covers kilometers, statute miles, meters and feet.

Checked against NIST Special Publication 811, Appendix B.8 (conversion factors: nautical mile 1,852 m, mile 1,609.344 m, knot 0.514444 m/s) and NOAA, "What is the difference between a nautical mile and a knot?" (updated September 23, 2026).