Libras (Castilian) to Pounds (libra to lb)
1 libra (Castilian) equals 1.014331436 pounds (rounded).
How to convert libras (Castilian) to pounds
To convert libras (Castilian) to pounds, multiply the number of libras (Castilian) by 1.014331436. The factor is rounded to 10 significant digits. To go the other way, multiply pounds by 0.9858710522 (rounded).
pounds = libras (Castilian) × 1.014331436
Example: 10 libras (Castilian) = 10.14331436 pounds.
Approximate value. Standards for the libra (Castilian) varied by place and period, so this converter uses the most commonly cited value. Treat results as estimates, not exact figures.
About these units
Libra (Castilian) (libra)
About 460.09 g, the Castilian pound. The Spanish libra and arroba were used throughout Spain and its colonies.
Latin libra, a pound, gave Castilian Spanish its basic weight, subdivided into 16 onzas of about 28 g each. Castile kept the unit through the Middle Ages, and the national standard enacted in 1801 fixed it at exactly 0.460093 kg, the figure used here. That is about 460 g, a little more than a half-ounce above the avoirdupois pound.
Before and after that decree, local libras differed a great deal. Huesca used one near 0.351 kg, Pontevedra one near 0.579 kg, and apothecaries in Barcelona used a medicinal libra of only 0.300 kg. Standardization on paper did not remove these customs quickly, so merchants had to know which city's pound a price referred to.
Larger Castilian weights were built from the libra. The arroba was 25 libras, about 11.5 kg, and the quintal 100 libras, about 46 kg. These were used for wool, olive oil, tobacco, silver and other goods across Spain and its American colonies until metric weights replaced them in the nineteenth century, though the libra survives informally as the pound in Latin America.
1 libra (Castilian) = 0.460093 kilograms (approximately).
Sources: Wikipedia: Spanish customary units; Wikipedia: Arroba
Pound (lb)
Exactly 0.45359237 kg, divided into 16 ounces. The standard unit of weight in the US and common in the UK.
Why is pound abbreviated lb? The answer is Roman. The English word comes from the Latin libra pondo, roughly the weight measured in libra, and the symbol keeps the first word. The Roman libra was divided into 12 unciae. The avoirdupois pound of 16 ounces came into general use around 1300 and was initially equal to 6,992 troy grains; under Elizabeth I it was redefined as 7,000 grains. The UK's Weights and Measures Act 1878 set the imperial standard pound as a platinum cylinder, and the troy pound was abolished for trade the following year.
Today the pound is defined from the kilogram. The International Yard and Pound Agreement of 1959 fixed it at exactly 0.45359237 kg, and the UK's Weights and Measures Act 1963 wrote the same figure into law. Pounds remain the everyday unit for body weight, groceries and shipping in the United States and are widely used in the UK. The word also survives in odd places: a six-pounder cannon was named for the weight of its shot, not its own.
1 pound = 0.45359237 kilograms (exactly).
Sources: Wikipedia: Pound (mass); NIST Guide to the SI, Appendix B.8 (mass conversions)
Related conversions
- Pounds to libras (Castilian) (reverse)
- Libras (Castilian) to kilograms
- Libras (Castilian) to grams
- Libras (Castilian) to metric tons
- Libras (Castilian) to ounces
- Kilograms to pounds
- Grams to pounds
- Metric tons to pounds
- Ounces to pounds
- Milligrams to pounds
- Micrograms to pounds
- Carats to pounds
- Stone to pounds
- Short tons to pounds
- Long tons to pounds
- Troy ounces to pounds
- Daltons to pounds
See all weight & mass units.