Which unit is commonly used to measure mass?

The kilogram is the standard unit of mass in the International System of Units (SI). It is a fundamental unit that is widely used in scientific contexts to quantify the amount of matter in an object. By definition, one kilogram is equivalent to the mass of the International Prototype of the Kilogram, a platinum-iridium cylinder stored in France.

In contrast, the meter is a unit of length, which measures distance rather than mass. The second is a unit of time, indicating duration, while the mole represents the amount of substance, specifically how many particles (such as atoms or molecules) are present in a given amount of matter. Thus, when discussing mass, the kilogram is the appropriate and standard unit to use.