Quick Answer
"LBS" comes from the Latin phrase "libra pondo," meaning "pound weight." The abbreviation "lb" is derived from "libra," the Latin word for scales or balance.
Have you ever wondered why we use "lbs" to abbreviate "pounds"? It seems completely unrelated at first glance, but this abbreviation has a fascinating history that dates back over 2,000 years to ancient Rome.
The story of "lbs" is more than just etymology—it's a window into how ancient civilizations influenced modern life, how language evolves across millennia, and why seemingly illogical abbreviations persist in our digital age.
The Roman Connection
Ancient Roman Origins
The Romans used a unit of weight called "libra pondo," which literally translates to "pound weight" or "a pound by weight." This phrase was eventually shortened to just "pound" in English, but the abbreviation stuck with the original Latin.
Latin Terms:
- Libra = scales, balance
- Pondo = weight, by weight
- Libra Pondo = pound weight
Modern Evolution:
- Libra → lb/lbs
- Pondo → pound
- Symbol → ℔ (historical)
The Zodiac Connection
Interestingly, the word "libra" is also connected to the zodiac sign Libra, represented by scales. This isn't a coincidence – both derive from the same Latin root meaning "balance" or "scales."
The Romans were meticulous about weights and measures, and their influence on modern measurement systems is still evident today.
Libra ♎
The Scales
Historical Timeline
Ancient Rome (753 BC - 476 AD)
Romans establish "libra pondo" as a standard unit of weight, approximately 327 grams.
Medieval Period (5th - 15th century)
The term spreads throughout Europe, with various regions adapting the measurement.
English Adoption (12th century)
English speakers adopt "pound" from "pondo" but keep "lb" from "libra" for abbreviation.
Modern Era (16th century - present)
Standardization of the pound and widespread use of "lb/lbs" abbreviation.
Other Latin-Derived Abbreviations
The pound isn't the only measurement with a Latin-derived abbreviation that seems unrelated to the English word:
International Variations
United States
- Uses "lb" and "lbs" commonly
- Avoirdupois pound = 453.592 grams
- Standard in everyday commerce
United Kingdom
- Mixed system: metric and imperial
- Still uses "lb" in some contexts
- Transitioning to metric system
Fun Facts About "LBS"
Currency Connection
The British Pound Sterling (£) also derives from "libra," showing the connection between weight and currency.
Astronomical Link
The constellation Libra represents the scales of justice, maintaining the balance theme.
Literary Usage
Shakespeare used "pound" in "The Merchant of Venice" - "a pound of flesh" - showing the term's long history in English.
Modern Usage Guidelines
Correct Usage:
- 5 lb (singular abbreviation)
- 5 lbs (plural abbreviation)
- 5 pounds (spelled out)
- 5-lb weight (adjective form)
Style Notes:
- No period after "lb" or "lbs"
- Space between number and abbreviation
- Use "lb" in technical writing
- Use "lbs" in casual contexts
Language Evolution in Action
The "lbs" abbreviation is a perfect example of how language evolves and preserves history. Every time you see "lb," you're looking at a 2,000-year-old piece of Roman culture that has survived through the ages!