What is the SI unit for mass?

The SI unit for mass is the kilogram. The International System of Units (SI) defines the kilogram as the base unit for mass, and it is crucial in scientific measurements and calculations. The kilogram is used because it is more convenient for a range of applications compared to smaller units.

The other units listed, such as grams and milligrams, are indeed commonly used in scientific contexts but are derived from the kilogram. For example, one kilogram equals 1,000 grams, and one gram equals 1,000 milligrams. While the pound is used in some regions, particularly the United States, it is part of the Imperial system rather than the SI system. Therefore, the kilogram is universally recognized as the standard unit of mass within the scientific community.