Knots to Miles Per Second (kn to mi/s)

1 knot equals 0.0003196609578 miles per second (rounded).

1 knot = 0.0003196609578 miles per second

How to convert knots to miles per second

To convert knots to miles per second, multiply the number of knots by 0.0003196609578. The factor is rounded to 10 significant digits. To go the other way, multiply miles per second by 3,128.314471 (rounded).

miles per second = knots × 0.0003196609578

Example: 10 knots = 0.003196609578 miles per second.

About these units

Knot (kn)

NauticalCurrent unit

One nautical mile per hour, exactly 1.852 km/h. The unit of speed for ships, aircraft and wind.

Knots in a rope really were counted. Before the mid-nineteenth century, sailors threw a weighted wooden board, the chip, off the stern on a line called the log-line. The line carried knots at regular intervals, and a sailor counted how many passed through his fingers while another timed the run with a sandglass. William Bourne's A Regiment for the Sea, printed in 1574, is the first known description, and many ships spaced knots 8 fathoms, about 14.6 meters, apart with a glass of roughly half a minute.

Today a knot is one nautical mile per hour, exactly 1,852 meters per hour, about 1.151 mph or 0.514 m/s. A ship making 1 knot along a meridian covers about one minute of latitude per hour, which is why charts and the unit fit together. It is not an SI unit, and the symbol is kn, though kt is common in aviation. Saying knots per hour is wrong, since that would describe acceleration. The US moved civil aircraft standards to nautical miles and knots in 1969, and winds and currents are also quoted in them.

1 knot = 0.5144444444 meters per second (approximately).

Sources: Wikipedia: Knot (unit); Wikipedia: Chip log; NIST Guide to the SI, Appendix B.8: conversion factors

Mile Per Second (mi/s)

US & ImperialCurrent unit

Exactly 1,609.344 m/s. Used for very high speeds.

Spaceflight speeds are where mile per second appears. Escape velocity from Earth's surface is 11.186 km/s, which is about 6.95 mi/s, found by dividing 11,186 m/s by 1,609.344 m. From the Moon the figure is 2.38 km/s, or about 1.48 mi/s, and a low Earth orbit at 7.7 km/s is about 4.8 mi/s, about 69 percent of the Earth escape figure.

The international mile is exactly 1,609.344 m, so one mile per second is exactly that many meters per second, and NIST lists the conversion as exact. It is also 5,793.6 km/h, and one meter per second is therefore about 0.00062 mi/s. NIST cautions that mile per second is not among the units it generally uses in its own publications.

1 mile per second = 1,609.344 meters per second (exactly).

Sources: Wikipedia: Escape velocity; NIST SP 811 Appendix B.8: conversion factors; Wikipedia: Orders of magnitude (speed)

Related conversions

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