An NFL broadcast says a wide receiver hit 22.5 ft/s on his route. What is that in km/h?

22.5 ft/s × 1.09728 = 24.69 km/h. That's roughly the pace of a fast recreational cyclist. Impressive on a football field, but the number sounds modest in road-speed terms.

A firearms manual lists muzzle velocity as 3000 ft/s. How fast is that in km/h?

3000 × 1.09728 = 3291.84 km/h — about Mach 2.7 at sea level. That's nearly three times the speed of sound and well into supersonic territory. For context, the Concorde cruised at around 2179 km/h.

My physics textbook gives a river current as 4.5 ft/s. Is that fast?

4.5 ft/s × 1.09728 = 4.94 km/h — a gentle walking pace. Most rivers run 2–5 ft/s; whitewater rapids can exceed 15 ft/s (16.5 km/h). See [mph to km/h](/speed/mph-to-kmh/) if your source uses mph instead.

How do I estimate ft/s to km/h in my head?

Multiply by 1.1 for a quick approximation. Example: 50 ft/s × 1.1 = 55 km/h (exact: 54.86 km/h). The error is under 0.15%, good enough for most comparisons.

Foot per Second to Kilometer per Hour Converter

Enter a value to instantly convert between speed units.

From

Precision4 dp

1 Foot per Second = 1.0973 Kilometer per Hour

Key Formulas

Kilometer per Hour → Mile per Hour

mph = km/h × 0.621371

Mile per Hour → Kilometer per Hour

km/h = mph × 1.60934

Knot → Mile per Hour

mph = kn × 1.15078

Mile per Hour → Knot

kn = mph × 0.868976

Formula

km/h = ft/s × 1.09728

Feet per second is standard in American physics, ballistics, and sports analytics, while kilometers per hour is the global standard for vehicle speeds and weather reporting. When a broadcast reports a linebacker ran 22 fps off the snap, or a lab report gives a projectile speed in ft/s, you need km/h to compare against road speed limits or international benchmarks.

Source: NIST SP 811, Table B.8

Frequently Asked Questions

Real-World Examples

Top speed of a fast NFL defensive end off the line — roughly a quick cyclist pace in km/h, but explosive over a 10-yard burst.

22 ft/s = 24.14 km/h

Usain Bolt's peak sprint speed during his 100 m world record — measured at his fastest 10 m segment, equivalent to 12.4 m/s.

40.7 ft/s = 44.67 km/h

Typical NFL punt speed at kick — the ball leaves the foot at roughly 70–80 fps, translating to highway speed in km/h.

75 ft/s = 82.3 km/h

Muzzle velocity of a high-powered rifle round — more than twice the speed of sound (1235 km/h) at sea level.

2800 ft/s = 3072.38 km/h

kmh to mph mph to kmh knots to mph mph to knots ms to kmh kmh to ms

Foot per Second to Kilometer per Hour Converter

Key Formulas

Formula

Frequently Asked Questions

Real-World Examples

Related Converters