What is the difference between 楼 and 层?

The short answer is that lóu (lóu) means “floor”, while céng (céng) is a classifier meaning “storey” or “layer”.

If you want to know more about classifiers, check out my post on Chinese Classifiers: What are they and how to use them as well as my complete list of Mandarin Chinese classifiers and measure words.

Suppose you wanted to talk about the fifth floor of a building:

dì wǔ céng lóu
(the) fifth storey floor

Breaking this down:

  • (dì wǔ) means “fifth”
  • céng (céng) means “storey”
  • lóu (lóu) means “floor”

You can shorten this sentence by leaving off characters, for example:

wǔ céng
storey five (fifth storey)

wǔ lóu
floor five (fifth floor)

dì wǔ céng
(the) fifth storey

dì wǔ lóu
(the) fifth floor

It is more common to simply say lóu or céng, however all combinations are used.

céng (céng) also has the meaning “layer”, while lóu (lóu) does not, so while you can say sāncéngdàngāo (sān céng dàngāo), meaning “three layer (tier) cake”, it is incorrect to say sānlóudàngāo (sān lóu dàngāo). Anywhere in English where you see the word layer, céng (céng) is normally the equivalent in Chinese, for example “adhesive layer” zhāncéng (nián hé céng) or ‘network layer” wǎngluòcéng (wǎngluò céng).