Import & Export Guides
Chinese Units of Measure for Importers: Jin, Cun, Si, Fang, Pi and Other Sourcing Traps
Oct
China officially uses the metric system, and formal export documents are normally in kilograms, metres and cubic metres. But the moment you leave the export paperwork and talk to factory staff on WeChat, browse listings on 1688 or Taobao, or read a domestic catalogue, you meet a set of traditional and trade units that are still in everyday use. Most are easy once you know them. The problem is that many importers do not know them, and the misunderstanding only appears when the goods arrive: plastic bags thinner than expected, a pipe fitting that does not match local plumbing, an air conditioner smaller than the customer wanted, or a price per jin mistaken for a price per kilogram.
This guide lists the units Bangladeshi importers meet most often, what each means, and the mistakes they cause.
Weight: jin, liang and gongjin
The jin is the most common source of confusion on Chinese domestic platforms. In mainland China the market jin is defined as 500 grams, half a kilogram. Prices on 1688 and in wholesale markets for food, spices, tea, hardware sold by weight and many raw materials are often quoted per jin.
- Jin: 500 g. A price per jin is half the price per kilogram you might assume, so the per-kilogram price is double the per-jin figure.
- Liang: 50 g, one tenth of a jin. Used for tea, herbs and small quantities.
- Gongjin: the kilogram, literally the metric jin.
- Dun: the metric tonne, 1,000 kg.
The mistake: an importer sees a low price per jin, assumes it is per kilogram, and is surprised when the invoice is double. Always ask suppliers to restate prices per kilogram or per piece in the proforma invoice.
Length: cun, chi, gongfen and the inch problem
Traditional Chinese length units are defined in metric terms in mainland China: the chi is one third of a metre and the cun is one tenth of a chi, about 3.33 cm. These appear in clothing, tailoring and some traditional products.
The bigger trap is that cun is also used informally to mean inch, which is properly called yingcun. Screen sizes, televisions, monitors, phone screens, wheel and tyre sizes, and some pipe and hose sizes are described in cun when the speaker means inches. A “32 cun” television is a 32-inch television. A product listing that switches between the two meanings can leave you guessing.
- Gongfen: centimetre. Limi is also centimetre, and haomi is millimetre.
- Mi: metre.
- Ma: yard, used in fabric trade.
The fix: ask for every critical dimension in millimetres on a drawing or specification sheet. Our guide on writing a product specification sheet shows how to lock this down.
Si: the unit behind thin plastic bags
In Chinese factory jargon, especially for plastic film, bags, sheet metal and coatings, si means 0.01 mm, one hundredth of a millimetre. A plastic bag quoted at 5 si is 0.05 mm thick. Packaging suppliers on 1688 almost always quote film thickness in si, and sometimes they quote single-layer thickness while the buyer assumes both layers of the bag together, or the other way round.
The mistake: an importer orders shopping bags or garbage bags expecting a certain thickness, but the supplier’s si figure referred to a different measurement basis. The bags arrive thinner than expected. Always state thickness in millimetres or microns, and say clearly whether it is single-wall or double-wall. Our packaging materials guide covers other packaging specs.
Fen: pipe and fitting sizes
In Chinese plumbing and pipe fittings, sizes are often given in fen, where one fen equals one eighth of an inch. So 4 fen is half an inch, 6 fen is three quarters of an inch, and 1 cun (one inch) is 8 fen. A supplier offering “4 fen” valves is offering half-inch valves.
The mistake: confusing fen with millimetres or with the outside diameter of plastic pipes, which are often sized by outside diameter in millimetres. Check whether your local market uses inch-based threaded fittings or metric plastic pipe sizes, and give the supplier the thread standard and size explicitly.
Fang: cubic metres in freight
Chinese freight forwarders and warehouses commonly say fang for cubic metre, the same thing as CBM. “3 fang” means 3 cubic metres. LCL rates are often quoted per fang. Our guide to revenue ton and W/M pricing explains how LCL charges are calculated once you know the volume. The related term lifang also means cubic metre.
Pi: air conditioner capacity
Air conditioners in the Chinese domestic market are described in pi, a traditional horsepower-based label. A 1 pi unit has a cooling capacity of roughly 2,500 watts, and 1.5 pi is roughly 3,500 watts, but pi is a marketing convention rather than a precise unit, and capacities vary between models. Bangladeshi buyers usually think in tons or BTU per hour.
The fix: ask for the rated cooling capacity in watts or BTU per hour, the power input and the voltage, from the nameplate or datasheet, not the pi label. Our guide on shipping HVAC equipment covers the import side.
Area and counting units
- Mu: a land area unit of about 667 square metres, used in agricultural machinery and greenhouse listings, for example a sprayer covering so many mu per hour.
- Pingfangmi or ping: square metre, used for tiles, panels and flooring.
- Jian: a piece or package; in logistics, jian often means a package or carton count.
- Xiang: carton. Tao: set. Dui: pair. Da: dozen.
- Gezhong (ke zhong): grams per square metre, gsm, for paper and fabric weight.
Counting units matter in quotations. A price per tao (set) and a price per jian (piece) can describe very different quantities. Make sure your proforma invoice states the unit price per clearly defined unit, and that the quantity column uses the same unit.
Quantity and money shorthand: wan, yuan, kuai and mao
Two more shorthand terms appear constantly in supplier chats. Wan means ten thousand, and Chinese speakers count large numbers in wan rather than thousands. A supplier saying “MOQ 1 wan” means 10,000 pieces, and “3 wan yuan” means 30,000 yuan. Misreading wan as a thousand is a tenfold error. Some suppliers write w or W after a number to mean wan, for example 5w for 50,000.
For money, yuan is the formal unit of the renminbi, kuai is the everyday spoken word for the same yuan, and mao is one tenth of a yuan. Domestic prices on 1688 are in yuan and usually exclude export packing, domestic freight to the port and sometimes VAT invoicing. When a supplier converts to US dollars for export, confirm which exchange rate and which costs are included. Our guide to 1688 vs Alibaba explains why domestic and export prices differ.
Quick reference table
| Chinese unit | Meaning | Common use |
|---|---|---|
| — | — | — |
| Jin | 500 g | Food, raw materials, prices on 1688 |
| Liang | 50 g | Tea, herbs |
| Cun | 3.33 cm, or informally an inch | Clothing, screens, tyres |
| Chi | One third of a metre | Tailoring, traditional goods |
| Si | 0.01 mm | Plastic film, bags, sheet thickness |
| Fen | One eighth of an inch | Pipe fittings and valves |
| Fang | Cubic metre | Freight and warehousing |
| Pi | Air conditioner size label | Domestic AC listings |
| Mu | About 667 square metres | Farm machinery coverage |
How to protect yourself
Write every critical specification in metric units on your purchase order or specification sheet, and ask the supplier to confirm it in writing. Ask for prices per kilogram or per piece. Request a sample before bulk and measure it. Our guides to communicating with Chinese suppliers and ordering samples cover the wider process. Unit confusion is cheap to prevent and expensive to fix after the goods have crossed the sea. Prices and specifications always depend on the exact product, so if a listing leaves you unsure, send it to us and ask us for a quote built around your specific product.
DE International’s team in China reads supplier listings and quotations in Chinese, converts every unit into clear specifications and confirms them in writing before you pay. Explore our services, browse the shop, use our China sourcing and buying agent service, or contact us. Related: buying from 1688 and Alibaba safely and comparing quotes from Chinese suppliers.
