Also depends on how much mass the weighed object has so not constant based on the position alone. But 9.81 or 9.8 is generally accepted as the acceleration due to gravity on earth. F=Gm1m2/r^2 if you’d like to be extra specific.

Kilogram is not the metric unit of weight, it’s mass. 1 liter of water has mass of 1kg. 1kg of water weighs 9.81 newtons - at least on earth. Newton is the metric unit of weight.