Feet per Second to Meters per Second Converter | ft/s to m/s

What this converter does

Feet per second is a speed you meet in particular corners of the technical world, and when a figure from one of them needs to sit in metric terms, this converter handles it. Enter a speed in ft/s and it gives you metres per second, the unit science and most of the world use. Type the value and read off the result.

Where feet per second shows up

This is not a unit most people use to talk about traffic. It lives in a few specific places. Ballistics quotes muzzle velocity in feet per second. The speed of sound is often given in ft/s. Engineers describe airflow through a duct or water through a pipe in feet per second. And US customary physics, where distances are in feet, naturally produces speeds in ft/s. So if you are holding a ft/s figure, it has probably come from one of those, and putting it into m/s lets it line up with metric data and formulas.

The factor, exact at 0.3048

One foot per second is 0.3048 metres per second, so:

m/s = ft/s × 0.3048

That 0.3048 is exact, because a foot is defined as exactly 0.3048 metres. So the conversion carries no rounding of its own. The m/s figure comes out smaller than the ft/s, since a metre is a bit longer than three feet.

A worked example

Sound travels through air at roughly 1,125 feet per second, and say you want that in metres per second.

• 1,125 × 0.3048 = 342.9 m/s

So the speed of sound is about 342.9 m/s, which is the figure you will see quoted in metric references. Converting the familiar ft/s value lets you check it against the m/s number physics uses, and the two agree, which is reassuring.

Common ft/s speeds in m/s

As an anchor, 100 ft/s is about 30.5 m/s, and the speed of sound near 1,125 ft/s is around 343 m/s.

Why convert to m/s

The reason is almost always that the next thing you do with the number is metric. Physics formulas run in metres and seconds, so a ft/s speed has to become m/s before it goes into a calculation of energy, force, or motion. Scientific data and international references report speeds in m/s, so converting lets you compare like with like. Even within engineering, a design that mixes US customary and metric inputs needs everything in one system first. Whenever a ft/s figure has to meet the metric world, this is the step that gets it there.

Questions people ask

How do I convert ft/s to m/s?

Multiply the speed in ft/s by 0.3048. The factor is exact, so the result is precise.

Is the conversion exact?

Yes. A foot is defined as exactly 0.3048 metres, so one foot per second is exactly 0.3048 m/s.

What is the speed of sound in m/s?

About 343 m/s in air, which comes from the roughly 1,125 ft/s often quoted in feet per second.

References

1. National Institute of Standards and Technology (NIST), Special Publication 811, Guide for the Use of the International System of Units (unit conversion factors). https://www.nist.gov/pml/special-publication-811
2. International Bureau of Weights and Measures (BIPM), The International System of Units (SI) Brochure (metre per second as the SI unit of speed). https://www.bipm.org/en/publications/si-brochure