science

Liang (mass)

Liang (mass) is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Liang (mass) rather than just read about it. In short: Liang (simplified Chinese: 两; traditional Chinese: 兩; pinyin: liǎng), or leung in Cantonese, liae in Wenzhounese, liong in Hakka, lian in Shanghainese, also called "Chinese ounce" or "tael", is a traditional Chinese unit for weight measurement. It originated in China before being introduced to neighboring countries in East and Southeast Asia.

Key takeaways

Liang (mass) belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Liang (mass) to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Liang (mass) from memory before moving on to harder problems.

Reference excerpt

Liang (simplified Chinese: 两; traditional Chinese: 兩; pinyin: liǎng), or leung in Cantonese, liae in Wenzhounese, liong in Hakka, lian in Shanghainese, also called "Chinese ounce" or "tael", is a traditional Chinese unit for weight measurement. It originated in China before being introduced to neighboring countries in East and Southeast Asia. Modern standards for the liang include 1/10 jin (50 grams) in mainland China, 37.5 grams in Taiwan, Korea and Thailand, 37.799 grams in Hong Kong, Singapore and Malaysia, and 37.8 grams in Vietnam. Liang is mostly used in traditional markets, and is a well-known measure for gold, silver and Chinese medicines.

Mainland China

Chinese mass units promulgated in 1915 On 7 January 1915, the Beiyang government promulgated a measurement law to use not only metric system as the standard but also a set of Chinese-style measures based directly on the Qing dynasty definitions (营造尺库平制).

where liang is the base unit, equal to 37.301 grams.

Mass units in the Republic of China since 1930 On 16 February 1929, the Nationalist government adopted and promulgated The Weights and Measures Act to adopt the metric system as the official standard and to limit the newer Chinese units of measurement to private sales and trade, effective on 1 January 1930. These newer "market" units are based on rounded metric numbers. And jin became the base unit.

where one liang is equal to 1/16 of a jin, or 31.25 grams.

Mass units in the People's Republic of China since 1959 On June 25, 1959, the State Council of the People's Republic of China issued the "Order on the Unified Measurement System", retaining the market measure system, with the statement of "The market system originally stated that sixteen liangs are equal to one jin. Due to the trouble of conversion, it should be changed to ten liangs per jin."

Legally, 1 jin equals 500 grams, and 10 liangs equal 1 jin (that is, 1 liang equals 50 grams). The traditional Chinese medicine measurement system remains unchanged.

Taiwan In 1895, Taiwan was ceded to Japan from China. The Japanese implemented the metric system, but the Taiwanese still followed their own habits and continued to use the old weights and measures of the Qing dynasty. 1 Taiwan liang is equal to 37.5 grams, or 1/16 Taiwan jin.

where liang is the base unit.

Hong Kong and Macau

Hong Kong and Macau mass units The liang is a legal weight measure in Hong Kong, and is still in active use. One liang is 37.799364167 g, and in Ordinance 22 of 1884 is 1+1⁄3 oz. avoir. Similar to Hong Kong, in Singapore, one tael is defined as 1+1⁄3 ounce and is approximated as 37.7994 g. In Hong Kong and Singapore, one liang is equivalent to 10 qian (Chinese: 錢; pinyin: qián) or 1⁄16 jin,. These Chinese units of measurement are usually used in Chinese herbal medicine stores as well as gold and silver exchange.

Similarly, Singapore law stipulates that one jin is also equal to sixteen liangs or 0.6048 kilograms, and one liang equals 37.799 g. Malaysia has the same regulations as it is a former British colony.

Hong Kong troy units These are used for trading precious metals such as gold and silver.

Korea The base unit of Korean weight is the gwan. One liang (兩, Korean ounce) is 1/100 of a gwan, or 37.5 g (1.32 oz).

Vietnam In Vietnam, the unit of liang is called "lang". In the time of French Indochina, the colonial administration fixed the (lạng) as 100 g, which is commonly used at food markets where many items typically weigh in the 100–900 g range. However, a different lang (called cây, lạng, or lượng) unit of 37.5 g is used for domestic transactions in gold. Real estate prices are often quoted in liangs of gold rather than the local currency over concerns over monetary inflation.

For more information on the Chinese mass measurement system, please see article Jin (mass).

Compounds wikt:幾斤幾兩 (jǐjīnjǐliǎng) wikt:半斤八兩 (bànjīnbāliǎng) wikt:缺斤少兩 (quējīnshǎoliǎng) wikt:銀兩 (yínliǎng)

Name of Tael The English word tael comes through Portuguese from the Malay word tahil, meaning "weight". Early English forms of the name such as "tay" or "taes" derive from the Portuguese plural of tael, taeis. Tahil ( in Singaporean English) is used in Malay and English today when referring to the weight in Malaysia, Singapore, and Brunei, where it is still used in some contexts especially related to the significant Overseas Chinese population.

See also Liang (currency) Chinese units of measurement Hong Kong units of measurement Taiwanese units of measurement Korean units of measurement Vietnamese units of measurement

Notes

References

External links 中國度量衡#衡 (in Chinese) 市制 (in Chinese) 兩 (in Chinese)

Illustrations

Worked examples

Example 1 — a first encounter with Liang (mass)

Start with the simplest possible case. Write down what Liang (mass) claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Liang (mass) before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Liang (mass) ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Liang (mass)

In research: Liang (mass) appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Liang (mass) in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Liang (mass) is common in secondary-school and first-year university syllabi. It links to neighbouring topics Chinese units of measurement, Customary units of measurement, Units of mass, so understanding it makes those chapters shorter.
In everyday life: Look for Liang (mass) outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Liang (mass) in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Liang (mass) means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Liang (mass) out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Liang (mass) in simple terms?

Why does Liang (mass) matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Liang (mass)?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Liang (mass).