Convert Feet per Second to Nautical Miles per Second
Convert Feet per Second (ft/s) to Nautical Miles per Second (nmi/s) instantly and accurately.
Conversion Formula
nmi/s = ft/s × 0.0001645788337
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.
About Nautical Miles per Second
A nautical mile per second (nmi/s) equals exactly 1,852 m/s - squarely in the hypersonic domain at approximately Mach 5.44 (ISA sea level). At this speed, kinetic energy per kilogram is ½ × 1852² ≈ 1.71 MJ/kg, comparable to a small shaped-charge detonation. Ballistic missile re-entry vehicles descend at roughly 3.8-7 nmi/s during the terminal phase; ICBM warheads at peak re-entry travel near 4-6 nmi/s. The US Navy's electromagnetic railgun programme aimed to accelerate 10 kg projectiles to approximately 1.7-2.5 nmi/s in test firings, giving them sufficient kinetic energy to destroy armoured targets without a warhead. Hypervelocity impact experiments at two-stage light-gas gun facilities reach similar speeds to simulate asteroid-impact cratering physics. The speed of sound in beryllium metal (the fastest known bulk acoustic medium) is approximately 12.9 nmi/s. 1 nmi/s = 1,852 m/s = 6,667.2 km/h = 3,600 kn ≈ Mach 5.44.
Quick Reference Table
| Feet per Second (ft/s) | Nautical Miles per Second (nmi/s) |
|---|---|
| 1 ft/s | 0.000164579 nmi/s |
| 2 ft/s | 0.000329158 nmi/s |
| 5 ft/s | 0.000822894 nmi/s |
| 10 ft/s | 0.00164579 nmi/s |
| 25 ft/s | 0.00411447 nmi/s |
| 50 ft/s | 0.00822894 nmi/s |
| 100 ft/s | 0.0164579 nmi/s |