kilogram-force [kgf] Unit Converter

Definition of kilogram-force [kgf] unit

The kilogram-force (kgf) is a non-SI unit of force equal to the gravitational force exerted on a mass of one kilogram under standard Earth gravity. It is defined exactly as 9.80665 newtons and is also called kilogram-force or kilopond.

History of kilogram-force [kgf] unit

The kilogram-force emerged from nineteenth-century gravitational measurement systems that used the kilogram as a mass standard and local gravity to define force. It became especially common in engineering, mechanics, and technical documentation before the International System of Units was adopted. In 1901, the General Conference on Weights and Measures established standard gravity as 9.80665 metres per second squared, giving the unit a fixed value. The SI later replaced it with the newton, formally making kilogram-force a non-SI unit, although older instruments and specifications still use it.

Applications of kilogram-force [kgf] unit

Kilogram-force appears in older engineering manuals, mechanical specifications, spring scales, torque tools, and some countries’ technical practice. It may describe loads, tensile strength, or appliance ratings, often as kgf/cm² for pressure. Modern scientific and industrial work generally converts it to newtons or pascals, but the unit remains useful when interpreting legacy data, equipment labels, and archived standards.

Complete list of kilogram-force [kgf] unit conversion