Foot per Second to Kilometer per Second

Foot per second measures the number of feet traveled in one second. Commonly used in engineering, ballistics, and some sports in the United States.

1 ft/s = 0.3048 m/s exactly (by definition of the international foot). 1 ft/s = 0.6818 mph.

To m/s: × 0.3048. To km/h: × 1.097. To mph: × 0.682. To knots: × 0.592.

Bullet velocities (handgun: 800–1,200 ft/s; rifle: 2,500–4,000 ft/s), waterfall flow rates, industrial conveyor speeds, and skydiving terminal velocity (120 ft/s).

Speed of sound: 1,125 ft/s at sea level. Free fall: 32 ft/s² acceleration. Skydiver terminal velocity: 120 ft/s. Baseball pitch: 132 ft/s (90 mph).

Confusing ft/s with mph — 1 ft/s is only 0.68 mph, not 1 mph. Also, mixing up ft/s and ft/min in HVAC calculations.

1 ft/s ≈ 0.3 m/s or ≈ 1.1 km/h. Quick check: 100 ft/s ≈ 70 mph. Multiply ft/s by 0.68 for approximate mph.

Kilometer per second measures how many kilometers an object travels in one second. Used for very high-speed phenomena like spacecraft, asteroids, and planetary motion.

1 km/s = 1,000 m/s = 3,600 km/h. There are 1,000 meters in a kilometer.

To m/s: × 1,000. To km/h: × 3,600. To mph: × 2,237.

Earth's orbital speed: 29.78 km/s. Moon's orbital speed: 1.02 km/s. Space shuttle orbital speed: 7.8 km/s. Meteor entry: 11–72 km/s.

Solar system escape velocity: 42 km/s. Voyager 1 speed: 17 km/s. Fastest star (S4714 near black hole): 24,000 km/s (8% light speed).

Underestimating the scale — 1 km/s is 3,600 km/h, extremely fast. Confusing with m/s (1000× smaller).

Think of km/s as 'space speeds.' Earth orbits at ~30 km/s. To escape Earth: 11.2 km/s. Moon orbit: ~1 km/s.