The newton (N) is the SI base unit of force, defined as the force needed to accelerate one kilogram of mass at one meter per second squared. Named after Isaac Newton, it is the fundamental unit in mechanics, structural engineering, and physics worldwide. One newton equals approximately 0.2248 pound-force.

Kilogram-force (kgf) is a non-SI unit defined as the gravitational force on one kilogram of mass at standard gravity, equal to exactly 9.80665 newtons. It is commonly used in some engineering fields and in countries transitioning from metric technical units to SI. One kilogram-force equals approximately 2.205 pound-force.