Korean units of measurement
Traditional Korean system of measurement, still used informally.
Korean traditional measurements, referred to as *cheokgwan-beop* or *cheokgeun-beop*, were historically used across the Korean peninsula. The system draws heavily from Chinese measurement practices, with later adjustments under Japanese rule after 1910. Today, both North and South Korea officially use the metric system. South Korea made commercial use of traditional units illegal in 2007, though informal use continues, especially the *pyeong* for floor space. North Korea still employs traditional units, but their values are now based on metric conversions.
**History**
Ancient Korea adapted the Chinese measurement system early on, with royal decrees imposing and adjusting standards over time. The system varied by region and era. Standardization relied on official rulers, ropes, odometers, triangulation tools, weights, cups, and basins. Although most measures were decimal, the convention was to list each place’s units separately—for example, “3 *cheok*, 1 *chon*, 4 *bun*, 1 *ri*”—rather than as a single decimal of the largest unit.
Under the Joseon dynasty, King Taejo established a Market Bureau (also called the Bureau of Weights and Measures) in 1392. Later, square brass rulers were introduced to standardize length, used by magistrates and secret police to prevent fraud. Social class determined how many *kan* (a bay between pillars, like the Japanese *ken*) a home could have. The 1496 Great Codex of State Administration (*Kyŏngguk Taejŏn*) included approved measures and verification procedures. It defined a *li* as 360 paces or 2,160 feet, though this conversion was not explicitly stated until a 1746 supplement. The 1897 Law on Weights and Measures, enacted after the Joseon declared the Korean Empire, unified local systems for the first time.
During Japan’s occupation (1910–1945), Japanese standards were imposed. Two common “traditional” units—the *pyeong* for floor space and the jeweler’s *don*—received their modern values under Japanese rule.
**South Korea**
South Korea signed the Metre Convention in 1959 and adopted the metric system under Park Chung Hee on May 10, 1961. A strict law banned the Korean pound, *li*, *gwan*, and *don* from January 1, 1964, with the *pyeong* banned after land registries converted. Metrication was not enforced for imports or exports, and enforcement was so spotty that the government abandoned attempts by 1970. Traditional units appear in many Korean sayings, literature, and poetry, including the national anthem’s “three thousand *lis* of rivers and mountains.” Further metrication efforts in 1983, 2000, and 2001 included TV and radio ads, brochures, signs, and contests praising metric and condemning traditional units. A common argument was that the units’ present values came from Japanese occupation; Yun Byeong-su of the Korea Association of Standards & Testing Organizations remarked that “even Japan has forsaken the *don* for grams and ounces but here we are standing around like idiots still blathering on about *don*.” Strong opposition from construction and jewelry industries, plus negative media coverage, led politicians to avoid the topic and regulators to accept dual use.
A 2006 study found 88% of real estate companies and 71% of jewelers in seven major markets still used *pyeong* and *don*. The government then criminalized commercial use of traditional units. Another factor was an EU regulation requiring metric for all imported goods by 2010. Sales of rulers marked in Korean feet ended. The Measure Act, effective July 1, 2007, allowed the Korean Agency for Technology and Standards to fine commercial users of *pyeong* and *don* up to ₩500,000, with less common units given longer grace periods. The ban also covered American units, such as inches for TV and monitor sizes. The informal “serving size” for meat cuts was standardized to 100 grams. Awareness of the fine remained low for years; it later rose to ₩1,000,000 (about $800) for users of illegal units and ₩3,000,000 for sellers of measuring devices with unapproved units. South Korea’s measurement standards are now maintained by the Korea Research Institute of Standards and Science.
Despite official discouragement, traditional units persist in retail, manufacturing, and farming. Even metric users often employ awkward metric fractions that equal round amounts of former units, especially the *pyeong*. The gold market avoided this by requiring pricing in even grams. Another workaround treats traditional units as a nondescript “unit,” such as marketing an air conditioner for a 20-*pyeong* home as a “20-Type.”
**North Korea**
Although the Soviet Union played a major role in establishing North Korea, Kim Il Sung continued official use of Korean units until...
- field
- Metrology
- nationality
- Korean
- known_for
- Traditional system of measurement including the pyeong, don, and li
- base_unit
- Foot (cheok), varying historically around 31.22 cm under Sejong the Great
Lore & Background
Customary Korean units, known as *cheokgwan-beop* or *cheokgeun-beop*, are a local adaptation of the traditional Chinese system, adopted at a very early date and adjusted over time by royal statutes. Standardization was accomplished through officially sanctioned rulers, ropes, odometers, triangulation devices, weights, cups, and basins. Although most measures operate on a decimal system, the traditional form was to read out each place value separately—for example, “3 cheok, 1 chon, 4 bun, 1 ri”—rather than as a single number of the largest unit. Under the Joseon dynasty, a Market Bureau was established in 1392, and later standardization efforts included square brass rulers used by magistrates and secret police to combat fraud. Different social classes were permitted different numbers of *kan* in their homes, where *kan* originally referred to the bay between two pillars rather than a fixed length. The 1496 Great Codex of State Administration included approved measures, defining a *li* as 360 paces or 2160 feet, though this conversion was not explicitly stated until a 1746 supplement. During Japanese occupation from 1910 to 1945, Japan imposed its standards, giving modern values to the *pyeong* of floorspace and the jeweler’s *don*. South Korea adopted the metric system in 1961, criminalizing commercial use of traditional units in 2007, though informal use continues, especially of the *pyeong*. North Korea still uses traditional units in approved sectors, with standards now derived from metric conversions.
Reader's Guide
Korean units of measurement represent a system deeply intertwined with the country's history, from ancient kingdoms through Japanese occupation to modern metrication efforts. The system's legacy is evident in Korean literature and poetry, including the national anthem's reference to 'three thousand lis of rivers and mountains.' The units also reflect Korea's complex relationship with foreign influence—Chinese origins, Japanese standardization, and later pressure to adopt the metric system for international trade. In North Korea, traditional units continue in government-approved sectors, illustrating how measurement systems can carry cultural and political weight. The ongoing informal use of units like the pyeong and don, despite fines and bans, underscores the challenge of fully replacing deeply embedded customary practices.
Did You Know?
- Under the Joseon dynasty, different classes of society were permitted different numbers of kan in their homes.
- North Korea's metrification initiative was announced in May 2013 as part of Kim Jong Un's policy stressing science and technology.
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