Miles per hour to knots

How to convert miles per hour to knots

1. Type a value in miles per hour into the converter above.
2. The answer in knots shows as you type. It uses the formula knots = miles per hour × 0.8689762419.
3. For example, 10 mph is 8.69 kn.

About miles per hour and knots

A knot is one nautical mile (1,852 m) per hour, and a mile is 1,609.344 m, so 1 mph is 0.868976 knots. Multiply mph by 0.869 to get knots. For a quick estimate take off 13%: 50 mph is about 43.5 knots against the exact 43.45.

You need this when a US news report, a road sign or a car speedometer gives miles per hour and a chart, a boat GPS or a marine or aviation forecast works in knots. Sailors and pilots in the US work in knots, while land forecasts give wind in mph.

Examples

• 10 mph (a 10 mph breeze) is 8.69 kn
• 39 mph (the start of tropical storm winds in US advisories) is 33.89 kn
• 111 mph (the start of Category 3, a major hurricane) is 96.46 kn
• 157 mph (the start of Category 5 on the Saffir-Simpson scale) is 136.43 kn

Miles per hour to knots chart