Is the kilogram the SI base unit for measuring?
The kilogram is the SI base unit for measuring the mass of an object, which when related to the pull of gravity on the object will
be recorded as its weight.
The kilogram is defined by a mass equal to that of a platinum-iridium prototype that defines the SI base unit of measure.
In physical calculations the mass of an object is not its weight, but its resistance to being put in motion or its resistance to any change in motion.
The weight of an object is actually a measure of the pull of gravity on the mass of the object. Still, most of our records will describe the weight of objects or substances in kilograms.