To clarify the question of how much kg is in a pound, and also where the name “pound” came from, we will have to go to ancient Rome.
In Rome, two names were used to indicate light weight. The word "libra" was used to denote the mass of precious metals and already minted coins. The weight of the remaining substances was measured in pounds. Let's take a closer look at each of the designations and find out how many pounds are kilograms, grams and ounces.
Most of us will probably have the first association with the word "pound" to be "pound sterling." Obviously, we are unlikely to find the answer to the question “how many kg in one pound,” but it is this expression that we find most often in everyday life, and it is unfair to deprive him of attention.
The pound to this day is the monetary unit of Great Britain, some of its former colonies and is indicated by the Latin letter L. It is easy to guess that this is so, because the name comes from the Latin name for the measure of weight "libra". As already mentioned, in the Roman Empire, libra was used to denote the weight, mainly precious metals. The libra was 327.45 grams and consisted of 12 ounces, each of which, in turn, was approximately 27 grams.
Ounces are still in motion. They range from 28 (fluid ounce) to 31 grams - this is the so-called “troy ounce”. The latter is used by jewelers and bank workers. A fluid ounce is still in demand among pharmacists and food manufacturers.
Pound sterling was originally one libre of sterling silver coins.
Then, with the development of the monetary system, banknotes and coins appeared that had nothing to do with the mass of silver that went into their production. The memory of the Roman source remained only in the form of a designation - the Latin letter L.
In Russia, a spool was attached to the libre. Probably everyone heard the saying that the spool is small, but expensive. Indeed, the spool was small and equal to about 4 grams of gold or 1/96 libra. So called a small gold coin of Kievan Rus.
A pound is another Roman measure of weight used to determine the mass of all other substances. And the answer to the question "how many kg per pound" should be addressed to her.
In Rome, the pound, like the libra, was 327 grams. But in medieval Europe, in every more or less significant region, sovereign gentlemen had the right to establish the value of the pound at their own discretion. And it should be noted that they actively used this right, extracting the maximum benefit for themselves from the answer to the question “how many kg per pound”.
In Europe, at the end of the eighteenth century, there were at least 100 different pounds. Their values ​​varied quite strongly among themselves. For example, the Austrian pound was equal to 560 grams, and the Spanish - 450. The French pound, called "livre", was equal to 490 grams and was also originally used, like the
British pound , to indicate the weight of silver coins. In Russia, the pound was 409 grams, and D.I. himself created his standard. Mendeleev.
It is clear that such a variety of designations of weight measures created a lot of inconvenience. Therefore, the metric system, with its kilograms and grams, was an excellent way out of the situation.
But it would be unfair to forget the pound. Therefore, now, after the adoption of the metric system, we can absolutely say exactly how many kg are in pounds. Today, a pound is by default equated to 500 grams.