Are market prices quoted per jin or per kilogram, and how do I calculate the bill?

At a glance

• A mainland market jin (斤) is 500 g; a kilogram (公斤 or 千克, kg) is 1,000 g, equal to two jin. A local market-supervision inspection explicitly uses this conversion when checking scales. [v 2-four-market-500 g]
• Market-regulator guidance says kilograms are the legal trade-settlement unit for scales; a spoken price per jin should not make an unclear scale display acceptable. [2]
• At RMB 10 per jin, the equivalent price is RMB 20 per kg. A0.75 kg purchase therefore costs RMB 15; these are worked arithmetic examples, not current fruit prices.
• At RMB 10 per kg, the same 0.75 kg costs RMB 7.50. Missing the quoted unit doubles the difference in this example.
• Huizhou's market-regulator explanation describes how price-unit and weighing-unit confusion can distort a bill. Compare the scale's unit and displayed unit price rather than looking only at its final total. [3]

What to do next

1. Before choosing a quantity, point to the product and ask whether the price is per jin, per kilogram, per piece or per box. Confirm the grade or variety too: two piles of similar-looking fruit can have different prices.
2. Convert the quote into one unit you can use. For example, write RMB 20/kg beside a spoken RMB 10/jin quote. On your phone, calculate price per kilogram multiplied by kilograms; this keeps the price and weight units consistent.
3. Ask for a manageable quantity before the seller cuts, cooks or packages anything. For the worked example,0.5 kg is one jin and 0.75 kg is one and a half jin. If you prefer a fixed spend, ask for about RMB 20 worth and agree whether the final weight may make it slightly higher or lower.
4. Watch the scale settle and identify the weight unit, unit-price field and total. Ask how the bag or container is handled before payment. If the display and the quote do not agree, ask the seller to explain or reweigh the item while it is still there.
5. Confirm the payable total on the scale or calculator before scanning the payment code. Keep the payment record and, for a disagreement, a clear photo of the quoted sign and weighing result rather than relying only on memory.
6. If you suspect a weighing problem, ask market management for an independent check using its available fair-weighing service. Keep the goods intact for that check and focus on the specific weight and price discrepancy.

If your situation is different

The stall quotes by piece or box: the jin-to-kilogram conversion is not the billing method. Ask the number of items or net quantity included and whether the quoted amount is for the whole package.

The product is cooked seafood or another prepared item: establish the raw or cooked weighing basis and any cooking charge before ordering. A cheap displayed ingredient price can be only one part of the total meal.

The seller gives a spoken per-jin quote but the scale shows kg: convert the unit price before comparing. RMB 10/jin should correspond to RMB 20/kg in the worked example, not RMB 10/kg.

You cannot read the display: ask the seller to put the weight, unit price and total on a calculator or piece of paper. Do this before the payment, while the amount can still be corrected easily.

Common mistakes

• Assuming every market in a city quotes the same unit: ask at the specific stall.
• Multiplying a per-jin price by a kilogram weight: convert one side first.
• Comparing prices without checking product grade or preparation charges: match the actual product and service.
• Using the payment amount alone to prove the weight: retain the displayed weight and unit-price information too.

Quick questions