The pound-force is a unit of force or weight (properly abbreviated "lbf"). The pound-force is equal to a mass of one pound multiplied by the standard acceleration of gravity (which is defined as exactly 9.80665 m/s², or exactly 196133/6096 feet/s², or approximately 32.17405 feet/s²).

In SI units, a pound-force is equal to exactly 4.4482216152605 newtons.