公斤
kilogram
gōngjīn
What does 公斤 mean?
公斤 (gōngjīn) is the metric kilogram — the standard unit of weight in mainland China and the rest of the metric world. It works as a measure word: number + 公斤 + noun (两公斤苹果 — two kilograms of apples; 我重六十公斤 — I weigh 60 kilograms). One thing English speakers should know: everyday Chinese shopping more often uses 斤 (jīn) — the traditional 'catty,' which equals 500 grams, exactly half a kilogram.
At a market, prices are usually quoted per 斤; in official, scientific, and most modern contexts, 公斤 is the unit. The 公 prefix means 'metric/public' and shows up in other metric units: 公里 (kilometer), 公升 (liter), 公分 (centimeter). When you say your body weight in modern conversation, 公斤 is the default.
Character breakdown
public; metric (prefix marking metric units)
catty (traditional Chinese weight unit, 500 g)
Memory hook: 公 'metric' + 斤 'catty' — the metric version of the catty, doubled up into a full kilogram.
Example sentences
我买了两公斤苹果。
Wǒ mǎi le liǎng gōngjīn píngguǒ.
I bought two kilograms of apples.
spoken
你多重？我五十五公斤。
Nǐ duō zhòng? Wǒ wǔshíwǔ gōngjīn.
How much do you weigh? I'm 55 kilograms.
spoken
这个箱子有多少公斤？
Zhège xiāngzi yǒu duōshao gōngjīn?
How many kilograms does this box weigh?
neutral
一公斤等于两斤。
Yī gōngjīn děngyú liǎng jīn.
One kilogram equals two jin.
neutral
Common phrases with 公斤
Synonyms
千克 is the scientific/official term for kilogram, used in textbooks, lab reports, and product labels. 公斤 is the everyday spoken word. Both mean exactly 1000 grams; pick by register.
Don't confuse 公斤 with
斤 is half a kilogram (500 g) — the traditional Chinese unit still used at markets and in recipes. 公斤 is double a 斤. Saying 一斤苹果 at a fruit stall is normal; saying 一公斤苹果 sounds slightly formal.
公里 is kilometer (distance), not kilogram (weight). Same 公 prefix, different unit. 五公斤 (5 kg) vs 五公里 (5 km).