Arroba

Arroba is a Portuguese and Spanish custom unit of weight, mass or volume. Its symbol is @.

History
The word arroba has its origin in Arabic ar-rubʿ (الربع) or "quarter," specifically the fourth part (of a quintal), which defined the average load which a donkey could carry.

Iberian Peninsula
In weight it was equal to 32 pounds (14.7 kg) in Portugal and 25 pounds (11.5 kg) in Spain.

The unit is still used in Portugal and Spain by cork merchants and pig farmers.

Arroba and bushel as weight units are similar (15 kg).

Latin America
The unit is still used in Brazil by the agricultural sector, mainly in the cotton and cattle business. The modern metric arroba used in these countries in everyday life is defined as 15 kg.

In Colombia, Ecuador, and Peru the arroba is equivalent to 12.5 kg.

In Bolivia nationally it is equivalent to 30.46 L. However locally there are many different values, ranging from 11.5 L in Inquisivi to 16 L in Baures.

Internet
In Spanish-speaking and Portuguese-speaking countries, "arroba" has continued as the word for the "@" symbol used in Internet email addresses.