Converter pounds to

One variation still used today is the Troy pound approx. The United States and countries of the Commonwealth of Nations agreed common definitions for the pound and the yard that were adopted in UK Scientific applications use the pound to describe mass, whilst everyday use sees it as a measure of weight. Despite broad acceptance of the metric system of weights and measures, the pound continues to be used in English-speaking countries.

The pound has historically been the means of describing the weight of shot or shells in weaponry, and the weapons themselves came to be named after the ammunition they would fire, for example a pounder. This convenience could be the reason that the system was more popular than other systems of the time that used 10, 12, or 15 subdivisions.

Current use: The pound as a unit of weight is widely used in the United States, often for measuring body weight. Many versions of the pound existed in the past in the United Kingdom UK , and although the UK largely uses the International System of Units, pounds are still used within certain contexts, such as labelling of packaged foods by law the metric values must also be displayed. The UK also often uses both pounds and stones when describing body weight, where a stone is comprised of 14 pounds.

It is currently defined based on the fixed numerical value of the Planck constant, h, which is equal to 6. Even though the definition of the kilogram was changed in , the actual size of the unit remained the same. The changes were intended to improve the definitions of SI base units, not to actually change how the units are used throughout the world.

SI is a system based on the meter-kilogram-second system of units rather than a centimeter-gram-second system. This is at least in part due to the inconsistencies and lack of coherence that can arise through use of centimeter-gram-second systems, such as those between the systems of electrostatic and electromagnetic units.

The kilogram was originally defined as the mass of one liter of water at its freezing point in , but was eventually re-defined, since measuring the mass of a volume of water was imprecise and cumbersome.

A new definition of the kilogram was introduced in based on Planck's constant and changes to the definition of the second.