Education Facts History

Here’s why ‘lb’ stands for ‘pound’


Normally, when we see an abbreviation, we can work out what word it’s the shortened form of. Abbreviations are common in the English language and are used for all sorts of things, from measurements to states in the country. If they’re so easy to understand, though, why are the letters “lb” used as a substitute for pounds? The word doesn’t use any of those letters, after all. Where’s the relevance?

The history of the “lb”

We grow up understanding that “lb” means pound the way that “yd” means yard and “tbsp” tablespoon, but we never question why. If we were to look into it, we’d find our answer relates back to the time of the Ancient Romans. That’s several thousand years we’re going back, so it’s no wonder the truth may have eluded us.

The letters “lb” actually originate from libra, a Latin word which was used to mean balance or scales. If anyone is familiar with astrology and star signs, you’ll know that libra is one of the signs of the zodiac. The seventh one, in fact, and its symbol is a scale – shocker. How does this relate to the specific weight of a pound, though?

Well, the word was also used in the unit of measurement libro pondo, which roughly translates to a pound weight. From there, the connection is pretty clear. The abbreviation “lb” takes into account the first word libra rather than the pondo that follows it. Considering that “lb” has been used in the English language since as early as the 14th century, they can’t really be blamed for choosing the wrong word to abbreviate. They had no way of knowing we’d all call it a pound 700 years later.

The British pound

If you’ve ever taken a trip to the UK or are just familiar with foreign currency, you’ll be familiar with the pound as a form of money. Once referred to as the pound sterling, this currency was named as such because its value used to equal that of a pound of silver. Makes sense, right? It was worth a pound; therefore it is a pound.

This coin doesn’t simply share its name with the unit of measurement that we’re fairly familiar with over here, but also with the roots of its name. The symbol used to refer to pounds in English money – £ – was actually a capital L back in the day. L for libra. Okay, that one might sound like a bit more of a stretch, but this is some cold, hard factual evidence we’re throwing your way.

What about ounce?

What about it? We didn’t say that we were going to talk about it. Did we? Well, while we’re on the subject of it, the ounce has a similar history rooted in Ancient Rome. As you may know, the abbreviation for ounce is oz, another short form that seems confusing. Where did the z come from?

Ounce derives from the word “uncia”, which is also where inch comes from. The word meant one-twelfth of something, back when 12 ounces equaled a pound rather than 16. Through the progress of time, ounce came into the English language by way of the French word “unce” (which sounds pretty similar). This also had origins from “uncia” as did the Italian word “onza” which is where the abbreviation “oz” originated. Why it was the Italian’s version that they ended up abbreviating we don’t know. Maybe they were fond of their pasta?

Whirlwind history lesson over. Now that we’ve unraveled those complicated abbreviations you’ll never be stumped by them again.