Newton (N)
In 1948, the General Conference on Weights and Measures designated the newton as the SI unit for measuring force, naming it in recognition of Sir Isaac Newton’s contributions to physics. Defined as the force needed to accelerate a 1-kilogram mass by 1 meter per second squared, the newton connects directly to the basic SI units for mass, distance, and time. It is the standard unit for quantifying force, weight, and pressure in scientific and engineering fields. This clear definition supports consistent international measurement and highlights the newton’s foundational role in science and technology.
Kilogram-force (kgf)
The kilogram-force, symbol kgf, defines a non-SI unit as the force Earth’s gravity exerts on one kilogram of mass at sea level, equal to 9.80665 newtons. Engineers and mechanics widely used it before the universal adoption of the SI. Today, users still find kilogram-force in older engineering documents, aviation, and certain regions. Its continued presence shows how mass-based and force-based units overlap, highlighting the transition from practical everyday measurements to the universal SI system.