Brazilian units of measurement

Lore & Background

Brazilian units of measurement were derived from Portugal and exhibited significant local variances. In 1814, as a colony, Brazil did not adopt the new Portuguese metric system based on the original metric system with traditional Portuguese names; instead, Portuguese customary units continued in use. In 1862, Law No. 1157 set a transition period for the metric system, but full compulsory adoption came later. The metric system was consolidated by the adoption of the International System of Units (SI) in 1973 (Law No. 5.966 of December 11, 1973).

Reader's Guide

Brazilian units of measurement represent a complex system of pre-metric measures that varied locally across the country. Length units included the pé (foot) equal to 0.33 m, with subdivisions such as the polegada (1/12 pé), palmo (2/3 pé), vara (3+1/3 pés), passo geométrico (5 pés), braça (6+2/3 pés), and légua (20,000 pés). Mass units were based on the libra (459.05 g), with the onça (1/16 libra), marco (1/2 libra), arroba (32 libras, though an arroba métrica equaled 15 kg and in Santos market Exchange one arroba was 10 kg), quintal (128 libras), and tonelada (1,728 libras). Special units for gems included the quilate (3.075 grains) and the outava for topazes (57.17 grains). Area measures varied greatly: one tarefa ranged from 3,000 to 4,000 m², and one alqueire could be 24,200 or 48,400 m². Volume units included the almude (31.944 L), with the alqueire ranging from 40 to 320 L (generally 33 L for grain, though other sources give values as low as 3.524 L). The cargueiro (mule load) consisted of two small barrels of 40 L each. These units reflect the decentralized nature of Brazilian commerce and agriculture before full metric adoption.

Did You Know?

• One pé (foot) was equal to 0.33 m, with local variations.
• One libra (pound) was equal to 459.05 g, with local variations.
• One arroba was 32 libras, but an arroba métrica equaled 15 kg, and in Santos market Exchange one arroba was 10 kg.
• One alqueire for volume ranged from 40 to 320 L, with different values for salt, common use, and Bahia.

A Mosaic of Regional Measures

Before Brazil embraced standardized measurement, the country relied on a sprawling collection of units inherited from Portugal, each subject to significant regional variation. Length was expressed through a hierarchy anchored by the pé, which measured roughly 0.33 meters but shifted slightly from one locality to another. From this base unit, smaller and larger measures were derived: the polegada (inch) was one-twelfth of a pé, the palmo (palm) two-thirds, and the vara (yard) stretched to three and a third pés. For greater distances, the passo geométrico spanned five pés, the braça (fathom) covered six and two-thirds, and the légua (league) stretched an enormous twenty thousand pés. Area measurement proved equally inconsistent. The tarefa ranged anywhere from 3,000 to 4,000 square meters depending on where one stood, while the alqueire could represent either 24,200 or 48,400 square meters. In Minas Gerais, the alqueire was further defined as eight salamis or thirty-three liters, illustrating how deeply local custom shaped what a unit actually meant in practice.

The 1814 Experiment and Its Quick Demise

In 1814, while still a constituent part of the Portuguese Empire, Brazil took a formal step toward modernization by adopting a new Portuguese metric system. This system drew on the original metric framework but retained traditional Portuguese names for its units, creating a hybrid that honored both the new rational standard and the old linguistic heritage. The intention was clear: to replace the chaotic tangle of regional measures with a single, coherent framework. Yet the reform proved short-lived. The new system failed to gain traction among the general population, who continued to rely on the familiar customary units they had always known. Within a relatively brief period, the metric adoption was effectively abandoned, and the old Portuguese measures—pés, varas, libras, almudes—resumed their dominant role in daily commerce and trade. The episode highlighted a fundamental challenge: a top-down imperial decree could not override the deeply ingrained measurement habits of a vast and diverse territory.

Weights, Measures, and the Weight of Local Custom

Mass measurement in pre-metric Brazil centered on the libra, which weighed approximately 459.05 grams, though local variations meant the exact figure could shift. From this base, a rich hierarchy unfolded: the onça was one-sixteenth of a libra, the marco half a libra, and the arroba a hefty thirty-two libras. The arroba itself was not uniform—a métrica arroba equaled fifteen kilograms, while in the Santos market exchange it was pegged at just ten. The quintal stretched to 128 libras, and the tonelada reached a massive 1,728. For precious stones, entirely separate units applied: the quilate (karat) for gems was 3.075 grains, and the outava, reserved for topazes, measured 57.17 grains. Volume was equally fragmented. The almude held 31.944 liters, and from it derived the canada (one-twelfth), the moio (ten almudes), the pipa (twelve), and the tonel (thirty). The alqueire for volume was notoriously inconsistent, ranging from 40 to 320 liters, with some sources citing values as low as 3.524 liters in Bahia. Even the cargueiro, a mule load of two 40-liter barrels, reflected the practical, animal-powered economy of the era.

From Compulsory Decree to Final Consolidation

The path from the failed 1814 experiment to full metric standardization in Brazil was neither quick nor smooth. For nearly half a century after the initial adoption was abandoned, the country continued to operate under its patchwork of Portuguese-derived customary units, with local variations persisting across regions. It was not until 1862 that the metric system was made compulsory, marking a decisive legislative break with the old measurement culture. This mandate forced merchants, artisans, and farmers alike to transition to a unified system, though the practical shift across such a vast territory undoubtedly took time to take full hold. The final chapter in this long transition came in 1972, when the metric system was formally consolidated, putting to rest any lingering legal ambiguity about which units were official. The journey from 1814 to 1972—spanning more than a century—underscores how deeply embedded traditional measurement practices were in Brazilian economic and social life, and how much political will and time were required to displace them. The Quebra-Quilos revolt, referenced alongside this history, hints at the social tensions that could accompany such a fundamental shift in how people measured their world.