What is centimetre per second?

Centimetre per second is a unit of speed used in low-velocity applications such as biological locomotion studies, microfluidics research, and slow-moving mechanical systems.

Real-world uses

Centimetres per second is used in the CGS system for fluid flow rates, sedimentation velocities in geology, and blood flow measurements in medical Doppler ultrasound. Glacier movement and tectonic plate motion are sometimes expressed in cm/s or cm/year.

History

Centimetres per second was the standard velocity unit in the CGS (centimetre-gram-second) system, widely used in physics until the mid-20th century. While SI uses m/s, cm/s persists in certain scientific fields, particularly fluid mechanics and geophysics.

Common mistakes

Confusing cm/s with m/s by forgetting the factor-of-100 difference. Also, assuming cm/s is too small for practical use—blood flow in major arteries is typically 10–40 cm/s, which is a very practical range.

What is knot?

A knot is a unit of speed equal to one nautical mile per hour, approximately 1.852 km/h. It is the international standard for maritime navigation, aviation, and meteorological wind speed reporting.

Real-world uses

Knots are the universal speed unit in maritime navigation and aviation worldwide, regardless of whether a country uses metric or imperial. Ship speeds, ocean currents, wind speed in aviation weather (METAR) reports, and jet stream velocities are all given in knots.

History

The knot originates from the 17th-century practice of measuring ship speed by throwing a log overboard attached to a rope with knots tied at regular intervals. Sailors counted how many knots paid out in a fixed time (measured by a sandglass).

Common mistakes

Saying "knots per hour"—a knot already means nautical miles per hour, so adding "per hour" is redundant and incorrect. Also, confusing knots with km/h: 1 knot ≈ 1.852 km/h.

When is this conversion used?

Converting between centimetre per second and knot is common when working across metric and imperial systems, such as international trade, travel between countries with different measurement standards, or following instructions from a different region.

Worked examples

1 centimetre per second = 0.01943844 knot

1 knot = 0.51444444 metre per second

How to convert centimetre per second to knot

To convert centimetre per second to knot, multiply the value by 0.01943844.

To convert knot back to centimetre per second, multiply by 51.44444444.

Measurement standards

The SI unit of speed is metres per second (m/s), a derived unit requiring no independent definition. The knot is defined as exactly one nautical mile (1,852 metres) per hour and is sanctioned for maritime and aeronautical navigation by the International Civil Aviation Organization.

Did you know?

The fastest human-made object is the Parker Solar Probe, which reached 635,266 km/h (about 176 km/s) in 2024 during a close pass of the Sun — fast enough to travel from New York to Tokyo in under a minute.

Quick reference: centimetre per second to knot

centimetre per second	knot
0.1	0.00194384
0.5	0.00971922
1	0.01943844
2	0.03887689
5	0.09719222
10	0.19438445
25	0.48596112
50	0.97192225
100	1.94384449
250	4.85961123
500	9.71922246
1,000	19.43844493

Common values

	centimetre per second	knot
Walking speed	140 centimetre per second	2.72138229 knot
City speed limit	1,390 centimetre per second	27.01943845 knot
Highway driving	3,130 centimetre per second	60.84233262 knot
Commercial aircraft	25,000 centimetre per second	485.96112315 knot
Speed of sound (sea level)	34,029 centimetre per second	661.47084239 knot

Available Speed units

More centimetre per second conversions

Assumption: Mach uses an approximate sea-level reference (about 340.29 m/s).