Knots to MPH Converter

The Knots to MPH Converter turns a speed in knots into miles per hour (mph) using the exact factor 1 knot = 1.150779 mph. Unlike a plain number converter, it also plots your speed on the Beaufort wind-speed scale, shows the matching storm or hurricane category, and gives you km/h, m/s and ft/s at the same time — so a value like "20 knots" instantly becomes something you can picture.

How to Convert Knots to MPH

The conversion is a single multiplication. One knot is one nautical mile per hour; a nautical mile is 1852 metres while a land (statute) mile is 1609.344 metres. Dividing the two gives the exact factor.

For a quick mental estimate, add about 15% to a knots value to get mph (20 kn + 15% ≈ 23 mph), or subtract about 13% from mph to get knots.

What Is a Knot?

A knot is a unit of speed equal to one nautical mile per hour, used in marine and air navigation and in meteorology. The name comes from the old practice of measuring a ship's speed by counting knots on a rope let out over the stern in a fixed time. Because one nautical mile equals one minute of latitude, speed in knots relates directly to distance on a navigational chart — which is exactly why sailors, pilots, and forecasters still use it.

The Beaufort Wind Scale (Knots, MPH, km/h)

The Beaufort scale connects a wind speed to what you can actually observe — from a mirror-flat sea to trees uprooting. This is the scale the converter draws above, so every conversion is anchored to a real effect.

Common Knots to MPH Conversions

Knots vs MPH: When Each Is Used

• Knots — sailing, boating, shipping, aviation, and weather reports for wind and marine forecasts. Tied to nautical miles and latitude.
• MPH — road speed and everyday use in the United States and United Kingdom. Tied to the statute (land) mile.
• km/h — road and general speed almost everywhere else in the world.
• m/s — the scientific SI unit, and the standard for wind speed in many national weather services outside the US.

How to Use This Converter

1. Enter the speed: Type the value you want to convert into the speed box.
2. Choose the direction: Keep it on Knots → MPH, or switch to MPH → Knots for the reverse.
3. Click Convert: The tool applies the exact 1.150779 factor instantly.
4. Read the result: See the mph value, the km/h, m/s and ft/s equivalents, the Beaufort force with its real-world effect, any matching storm or hurricane category, and a step-by-step breakdown.

Frequently Asked Questions

How do you convert knots to mph?

Multiply the speed in knots by 1.150779 to get miles per hour. One knot is one nautical mile per hour, and one nautical mile is 1852 metres while one land mile is 1609.344 metres, so 1 knot equals 1852 ÷ 1609.344 = 1.150779 mph.

What is 20 knots in mph?

20 knots equals about 23.02 mph (20 × 1.150779). As a wind speed that is roughly Beaufort Force 5, a fresh breeze.

Why are knots used instead of mph?

Knots are based on nautical miles, which are tied to one minute of latitude on the Earth. Because one nautical mile equals one minute of arc, a speed in knots relates directly to position on a chart, which is why marine and aviation navigation use knots.

Is 1 knot exactly 1.15 mph?

Almost. One knot is exactly 1.150779448 mph, usually rounded to 1.15 mph. Adding about 15% to a knots value gives a close mph estimate for quick mental math.

What is the Beaufort wind scale?

The Beaufort scale rates wind from Force 0 (calm, under 1 knot) to Force 12 (hurricane force, 64 knots and above). It links a wind speed to observable effects on sea and land, so a converted speed can be understood in real terms, not just as a number.

How many knots is hurricane force?

Hurricane force begins at 64 knots, which is about 74 mph. That is the threshold for a Category 1 hurricane on the Saffir-Simpson scale and Beaufort Force 12.

Additional Resources

• Knot (unit) - Wikipedia
• Beaufort Scale - Wikipedia