644 meters per second in knots

Conversion

644 meters per second is equivalent to 1251.83585313175 knots.^[1]

Conversion in the opposite direction

The inverse of the conversion factor is that 1 knot is equal to 0.000798826777087647 times 644 meters per second.

It can also be expressed as: 644 meters per second is equal to $\frac{1}{0.000798826777087647}$ knots.

Approximation

An approximate numerical result would be: six hundred and forty-four meters per second is about one thousand, two hundred and fifty-one point eight three knots, or alternatively, a knot is about zero times six hundred and forty-four meters per second.

Units involved

This is how the units in this conversion are defined:

Meters Per Second

"Meter per second is an SI derived unit of both speed (scalar) and velocity (vector quantity which specifies both magnitude and a specific direction), defined by distance in metres divided by time in seconds.The SI unit symbols are m·s−1, m s−1, m/s, or m/s, sometimes (unofficially) abbreviated as mps. Where metres per second are several orders of magnitude too slow to be convenient, such as in astronomical measurements, velocities may be given in kilometres per second, where 1 km/s is 1000 metres per second, sometimes unofficially abbreviated as kps."

Wikipedia page of meters per second

Knots

"The knot (/nɒt/) is a unit of speed equal to one nautical mile (1.852 km) per hour, approximately 1.151 mph. The ISO Standard symbol for the knot is kn. The same symbol is preferred by the IEEE; kt is also common. The knot is a non-SI unit that is accepted for use with the SI. Worldwide, the knot is used in meteorology, and in maritime and air navigation—for example, a vessel travelling at 1 knot along a meridian travels approximately one minute of geographic latitude in one hour. Etymologically, the term derives from counting the number of knots in the line that unspooled from the reel of a chip log in a specific time."

Wikipedia page of knots

Footnotes

[1] The precision is 15 significant digits (fourteen digits to the right of the decimal point).

Results may contain small errors due to the use of floating point arithmetic.