Convert Speed of Light to Feet per Second

Convert Speed of Light (c) to Feet per Second (ft/s) instantly and accurately.

Speed of Light (c)
Feet per Second (ft/s)

Conversion Formula

ft/s = c × 983571056.4

About Speed of Light

The speed of light in vacuum (c) = exactly 299,792,458 m/s - the defined SI constant from which the metre is derived (since 1983) and the universal speed limit of causality. Light from the Sun reaches Earth in 8 min 20 s; from the Moon in 1.28 s; from Proxima Centauri in 4.24 years. Mars communication delay 3-22 minutes. In optical fibre (n ≈ 1.467), c/n ≈ 200,000 km/s. GPS clocks must correct for both special and general relativistic effects. c = 299,792,458 m/s.

About Feet per Second

A foot per second (ft/s) = exactly 0.3048 m/s - the primary speed unit in US ballistics, hydraulics, and gas dynamics. .308 Winchester muzzle velocity ~2,750 ft/s; 9mm pistol 1,200-1,400 ft/s; .50 BMG 2,910 ft/s. Speed of sound at sea level 1,116 ft/s. River channel mean velocities 0.5-6 ft/s; NFPA sprinkler pipe flows also in ft/s. 1 ft/s = 0.3048 m/s = 1.09728 km/h = 60 ft/min.

Quick Reference Table

Speed of Light (c)Feet per Second (ft/s)
1 c983571000 ft/s
2 c1.967 × 109 ft/s
5 c4.918 × 109 ft/s
10 c9.836 × 109 ft/s
25 c2.459 × 1010 ft/s
50 c4.918 × 1010 ft/s
100 c9.836 × 1010 ft/s

→ Full Speed Converter