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.

The kilonewton (kN) equals 1,000 newtons, used in structural engineering to express building loads, bridge capacities, and material strength ratings. A typical passenger car weighs about 10–15 kN, and building codes specify design loads in kN per square meter. One kilonewton equals approximately 224.8 pound-force.