What is foot per second?

Foot per second is a unit of speed in imperial and US customary systems. It is used in ballistics, sports science, and engineering calculations that rely on US customary units.

Real-world uses

Feet per second is used in ballistics for bullet muzzle velocities (e.g., 2,800 fps for a rifle round), aerospace engineering for aircraft approach speeds, and fluid dynamics in American engineering contexts. Elevator speeds are sometimes specified in ft/s.

History

Feet per second has been used in English-language engineering since the 18th century, particularly in artillery and ballistics. It remains the standard velocity unit in American firearms and aerospace industries despite the broader shift toward metric units.

Common mistakes

Confusing feet per second with miles per hour. 1 ft/s ≈ 0.682 mph, so they are quite different. Also, using fps as an abbreviation for both "feet per second" and "frames per second" creates ambiguity in technical documents.

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.

When is this conversion used?

Converting between foot per second and centimetre per second 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 foot per second = 30.48 centimetre per second

1 centimetre per second = 0.01 metre per second

How to convert foot per second to centimetre per second

To convert foot per second to centimetre per second, multiply the value by 30.48.

To convert centimetre per second back to foot per second, multiply by 0.0328084.

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: foot per second to centimetre per second

foot per second	centimetre per second
0.1	3.048
0.5	15.24
1	30.48
2	60.96
5	152.4
10	304.8
25	762
50	1,524
100	3,048
250	7,620
500	15,240
1,000	30,480

Common values

	foot per second	centimetre per second
Walking speed	4.59317585 foot per second	140 centimetre per second
City speed limit	45.60367454 foot per second	1,390 centimetre per second
Highway driving	102.69028871 foot per second	3,130 centimetre per second
Commercial aircraft	820.20997375 foot per second	25,000 centimetre per second
Speed of sound (sea level)	1,116.43700787 foot per second	34,029 centimetre per second

Available Speed units

More foot per second conversions

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