Convert Jin/Catty (China) to grams

A traditional unit rebuilt on the kilogram

The 1959 reform did not abolish the jin; it re-anchored it. By setting the shìjīn at exactly half a kilogram, the state kept the unit people used while making every conversion trivial and exact. A price per jin is a price per half-kilo, and the two can be quoted interchangeably on the same label — which is exactly what wet markets and supermarkets across the mainland do.

That decision is the reason mainland jin figures need no qualification. Unlike the bigha or the seer, the modern mainland jin has one value, and it is exact by statute rather than by convention.

Hong Kong and Taiwan did not follow

Hong Kong retained the older catty of 1⅓ pounds avoirdupois — about 604.79 grams — and it remains a legal trade unit there under the Weights and Measures Ordinance. Taiwan kept the Japanese-era kin of exactly 600 grams. A wholesale quote in "catty" can therefore mean three different masses depending on which side of a border the seller sits, spanning roughly 21 per cent.

Singapore and Malaysia historically used the Hong Kong value of about 604.79 g for the kati. Because these markets trade with each other constantly, a cross-border quote should always name the jurisdiction, not just the unit.

The tael inherits the split

One catty is 16 taels everywhere the unit survives, so every jin value produces a corresponding tael value: 31.25 g on the mainland, about 37.80 g in Hong Kong, 37.5 g in Taiwan. The Hong Kong tael is the one that matters most financially — it is the trading unit of the Chinese Gold & Silver Exchange Society, so gold contracts settle on it.

For traditional medicine, the qian (one-tenth of a tael) and fen (one-hundredth) continue the same ladder. A prescription written in qian carries whichever jurisdiction's tael the pharmacy works to, which is why herbal dosing references specify the region.

Working with jin in trade and recipes

For food imports, the safest default when the source jurisdiction is unstated is the mainland 500 g jin, simply because it dominates volume. For precious metals the safe default is the Hong Kong tael. Neither default replaces asking.

In recipes, the half-jin (250 g) is the most common practical quantity and maps neatly onto metric kitchen scales. Converting a mainland recipe by treating the jin as a pound understates every quantity by about 10 per cent — enough to matter in baking, not enough to be obvious in a stir-fry, which is precisely why the error persists.

Bulk agricultural statistics from China are usually published in tonnes rather than jin, but per-capita and per-mu figures in provincial yearbooks are often given in jin, and the two appear in adjacent tables. Because a jin is exactly half a kilogram, a jin figure read as a kilogram figure doubles the result — a clean, silent error that survives plausibility checks. Reading the column header rather than inferring the unit from magnitude is the only defence.

Common mistakes to avoid

• Mainland jin = 500 g exactly; Hong Kong catty ≈ 604.79 g; Taiwan jin = 600 g.
• The jin is not a pound — treating it as one understates quantities by about 10 per cent.
• Gold quoted in tael almost always means the Hong Kong tael (≈37.80 g).
• A catty quote in Malaysian or Singaporean trade documents usually follows the Hong Kong value.