Is a Knot faster than an MPH?

Yes, a Knot is faster. One Knot equals one nautical mile per hour (roughly 1.15 MPH). Because a nautical mile is longer than a statute mile, you cover more distance in one Knot than in one MPH.

What is the formula for MPH to Knots?

The formula is: Knots = MPH ÷ 1.15078. This accounts for the difference between a standard mile (5,280 ft) and a nautical mile (approx. 6,076 ft).

Convert Miles per Hour to Knots (MPH to KN)

Converting Miles per Hour to Knots (mph to kn) is often necessary for sailors and pilots interpreting weather reports meant for the general public. While TV meteorologists report wind speeds in mph, nautical charts and aircraft instruments rely on Knots. Since a Knot is based on latitude (nautical miles) rather than land miles, it is a “faster” unit. This means 100 mph is actually a lower number in Knots.

mph to Knots Converter

Miles per Hour (mph)

Knots (kn)

Enter a value above

Master Speed Converter

Speed Value

From

The Formula

Multiply the mph by 0.869:

mph × 0.869 = kn

Example

If the wind speed is 50 mph:

50 × 0.869 = 43.45 kn

Travel & Navigation Velocity Insights

💡 The “Minus 15 Percent” Shortcut

Since a Knot is roughly 15% “larger” than an MPH, your speed in Knots will always be a lower number than your speed in MPH. If you are looking for a quick estimate, subtract about 13-15% from your MPH value to find your speed in Knots.

Highway Speed: 70 MPH is roughly 60.8 Knots.

City Limit: 30 MPH is roughly 26.1 Knots.

Frequently Asked Questions

Why do boats use Knots instead of MPH?

Knots are based on nautical miles, which are directly related to the Earth’s latitude. One nautical mile is exactly one minute of arc on a chart. This makes it much easier for sailors and pilots to calculate their position on a globe than using standard “statute” miles, which have no relationship to the Earth’s geometry.

How do I convert MPH to Knots in my head?

A simple trick is to subtract 1/8th from your MPH. For example, if you are going 40 MPH, 1/8th of 40 is 5. Subtracting 5 gives you 35 Knots. The exact answer is 34.76, so this mental math gets you within a fraction of a point!

What is a ‘Statute Mile’?

The “statute mile” is the 5,280-foot mile we use for MPH on road signs. It was originally defined by law (statute) in England. In contrast, the nautical mile is a “geographical mile,” which is why the two units differ in length and why 100 MPH feels different than 100 Knots.