Feet Per Second
Also: fps · FPS
The standard US unit for bullet speed. A 6.5 Creedmoor load running 2,800 fps is at the typical middle of its working window.
Always written “fps,” never “f/s” or “ft/sec.” Most commercial cartridges run between 1,000 fps (subsonic) and 3,400 fps (light bullets in overbore magnums). A useful mental anchor: the speed of sound at sea level is roughly 1,125 fps.
For metric conversions, 1 fps ≈ 0.305 m/s. Internationally published data usually uses m/s; US shooting culture uses fps universally.