Kilogram-force

A kilogram-force (kgf) is a unit of force that will accelerate 1 kilogram of mass at 9.80665 m/s², the standard acceleration due to gravity on Earth's surface (referred to as g_n). The kilogram-force is often referred to as the kilopond (kp).

Since a newton is defined as the force that will accelerate 1 kilogram of mass at 1 m/s², and acceleration is proportional to force, one kilogram-force is therefore equal to 9.80665 newtons. It is also equal to 2.20462 pounds-force.

The kilogram-force was not very well defined until the 3rd General Conference on Weights and Measures (Conférence Générale des Poids et Mesures, CGPM) defined g_n, the standard gravity, to be 9.80665 m/s² in 1901. Although it was once widely used, it has never been part of the International System of Units (SI) introduced in 1960 by the 11th GCPM.

The kilogram-force is still used to some extent in a few countries, but it is generally considered to be obsolete in most countries.

Equivalent units of force

• 1 kgf ≡ 9.80665 newton (symbol: N)
• 1 kgf ≡ 980,665 dyne (symbol: dyn)
• 1 kgf ≡ 1 kilopond (symbol: kp)
• 1 kgf ≡ 9.80665×10^-3 sthène (symbol: sn)
• 1 kgf ≈ 2.20462 pound-force (symbol: lbf)
• 1 kgf ≈ 2.20462×10^-3 kip (symbol: kip)
• 1 kgf ≈ 70.93164 poundal (symbol: pdl)