The kilogram (kg) is the base unit of mass in the International System of Units, defined by the Planck constant since 2019. It is the most widely used mass unit globally for body weight, grocery items, and shipping, appearing on scales in homes and markets everywhere. One kilogram equals roughly 2.2046 pounds.

The metric ton or tonne (t) equals 1,000 kilograms and is used for measuring heavy cargo, industrial output, and vehicle weights worldwide. Shipping containers, steel production, and greenhouse gas emissions are all commonly reported in tonnes. One tonne equals approximately 2,204.6 pounds or about 1.1023 short tons.