Knots to mph Converter

knots to miles per hour formula

mph = knots × 1.150779448

1 knot = 1.150779448 miles per hour, so multiply knots by 1.150779448. Going the other way, 1 mile per hour = 0.8689762419 knots.

knots to miles per hour table

How many miles per hour in knots?

1 kn = 1.15078 mph. There are 1.15078 miles per hour in 1 knots.

10 kn = 11.5078 mph. There are 11.5078 miles per hour in 10 knots.

20 kn = 23.0156 mph. There are 23.0156 miles per hour in 20 knots.

34 kn = 39.1265 mph. There are 39.1265 miles per hour in 34 knots.

64 kn = 73.6499 mph. There are 73.6499 miles per hour in 64 knots.

miles per hour to knots formula

knots = mph ÷ 1.150779448

1 mile per hour = 0.8689762419 knots, so multiply miles per hour by 0.8689762419, or divide by 1.150779448.

miles per hour to knots table

How many knots in miles per hour?

1 mph = 0.868976 kn. There are 0.868976 knots in 1 miles per hour.

10 mph = 8.68976 kn. There are 8.68976 knots in 10 miles per hour.

30 mph = 26.0693 kn. There are 26.0693 knots in 30 miles per hour.

74 mph = 64.3042 kn. There are 64.3042 knots in 74 miles per hour.

100 mph = 86.8976 kn. There are 86.8976 knots in 100 miles per hour.

How the Knots To Mph works

Knots to mph: the factor

The nautical mile is exactly 1,852 m and the statute mile exactly 1,609.344 m. Divide and a knot is 1.150779 mph. The converter uses the full figure. For an estimate add 15%: 20 knots is 23 mph (exact: 23.0). Treating knots and mph as the same is the common error, and it is 15% out.

Worked example: a 34 knot gale

34 × 1.150779 = 39.1 mph. The shipping forecast and marine warnings are in knots; the land forecast on the same broadcast is in mph, so the same weather system carries two numbers. Beaufort force 8, gale, begins at 34 knots, 39 mph; force 10, storm, at 48 knots, 55 mph; force 12, hurricane, at 64 knots, 74 mph.

Worked example: a Category 3 hurricane at 100 knots

100 × 1.150779 = 115 mph. The Saffir-Simpson scale is defined in knots and quoted in mph: Category 1 starts at 64 knots, 74 mph; Category 3 at 96 knots, 111 mph; Category 5 at 137 knots, 157 mph. Reports that quote "sustained winds of 115 mph" have done this conversion.

Boats

A cruising sailing yacht makes 6 knots, 6.9 mph, a fast walk. A cross-Channel ferry at 22 knots is 25 mph; a motor cruiser at 30 knots is 35 mph; a racing powerboat at 100 knots is 115 mph. A ship's speed limit from hull length is about 1.34 × √(waterline in feet), in knots.

Aircraft

A light aircraft at 100 knots is 115 mph; an airliner's 470 knot cruise is 541 mph, and its 140 knot approach is 161 mph. Airspeed indicators read knots everywhere, including in America, where road speeds are in mph, so pilots convert constantly.

km/h and m/s

1 knot is 1.852 km/h and 0.5144 m/s. The knots to km/h page covers the metric road figure; wind data in metres per second converts through the m/s to km/h page. All three appear in a single weather briefing.

Worked example: a 74 mph hurricane threshold

74 × 0.868976 = 64.3 knots. The Saffir-Simpson scale is defined in knots: Category 1 begins at 64 knots, which is 73.6 mph and gets rounded to 74. Category 3 is 96 knots, 111 mph; Category 5 is 137 knots, 157 mph. The Beaufort hurricane force 12 uses the same 64 knot line.

Worked example: a 20 mph forecast

20 × 0.868976 = 17.4 knots. British land forecasts are in mph and the shipping forecast in knots, so a 20 mph breeze on land is force 5 at sea, 17 to 21 knots. Gale force 8 begins at 34 knots, 39 mph; a strong wind warning for small craft is issued at 22 knots, 25 mph.

Knot to miles per hour formula and table

The formula on this page is mph = knots × 1.150779448, applied exactly before rounding for display.

How many miles per hour in 1 knot? 1 kn is 1.1508 mph. Likewise 10 kn is 11.51 mph, 20 kn is 23.02 mph, 34 kn is 39.13 mph.

Knot to mile per hour conversion table

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