Convert kilometers per hour to feet per second easily.

Ever wondered how fast a cheetah sprinting at 100 km/h is in feet per second? Or maybe you’re designing a roller coaster and need to translate metric speed data into imperial units for a U.S. client. Whatever your reason, converting kilometers per hour (km/h) to feet per second (ft/s) doesn’t have to feel like solving a Rubik’s Cube blindfolded. Let’s break it down so you can move from confused to confident in under five minutes.

Unit definitions

What is a kilometer per hour (km/h)?

Description: Kilometers per hour measures how many kilometers an object travels in one hour.
Symbol: km/h
Common uses: Road speed limits, weather wind speeds, vehicle dashboards.
Definition: 1 km/h = 1000 meters traveled in 3600 seconds.

What is a foot per second (ft/s)?

Description: Feet per second measures distance in feet traveled over one second.
Symbol: ft/s
Common uses: Physics experiments, engineering projects, ballistics.
Definition: 1 ft/s = 12 inches traveled in 1 second.

Conversion formula

To convert km/h to ft/s, multiply the speed by 0.911344.
Formula: ft/s = km/h × 0.911344

Example calculations

1. Converting 60 km/h to ft/s:
   60 × 0.911344 = 54.68 ft/s (roughly the speed of a car on a highway).
2. Converting 120 km/h to ft/s:
   120 × 0.911344 = 109.36 ft/s (about the top speed of a peregrine falcon diving).

Conversion tables

Kilometers per hour to feet per second

Feet per second to kilometers per hour

Historical background and modern use

The kilometer per hour became standard during the 19th century as railroads expanded across Europe, needing consistent speed metrics. Feet per second, however, has roots in ancient Rome, where the "pes" (foot) measured military pacing. Funny enough, the metric system was designed to unify measurements, but the U.S. held onto feet—partly due to the cost of switching industrial equipment. Today, km/h dominates global transportation, while ft/s hangs on in niche fields like acoustics (sound travels ~1125 ft/s in air). The persistence of both units shows how history and practicality shape measurement systems, even when it’s not always the most efficient path.

Interesting facts

1. The fastest human sprint (44.72 km/h by Usain Bolt) equals about 40.9 ft/s.
2. A sneeze travels ~16.67 ft/s, which is 18.29 km/h.
3. NASA uses ft/s for spacecraft re-entry speeds but km/h for rover missions.
4. The term “knots” (nautical miles per hour) is more common than ft/s in maritime contexts.
5. Japan’s Shinkansen trains hit 320 km/h—roughly 292.9 ft/s.

FAQ