Kilogram-force (kgf) is a unit of force that represents the gravitational force exerted on a mass of one kilogram at standard gravity. It is defined as the force required to accelerate a mass of one kilogram at a rate of 9.81 m/s², which is the acceleration due to Earth's gravity. In practical terms, one kilogram-force is equivalent to approximately 9.81 newtons (N). This unit is often used in engineering and physics to simplify calculations involving weight and force, especially in contexts where mass and gravitational effects are relevant.