"What's that got to do with the -- ?" is an expression which is used to denote something which is unrelated to the current topic of discussion.

A common form "what does that have to do with the price of tea {rice} in China?", is a retort to an irrelevant suggestion. This facetious usage implies that the topic under discussion might as well be the price of tea in China for all the relevance the interlocutor's suggestion bears on it. It has been said[by whom?] that this expression has stemmed from economists, who describe everything economic as affecting everything else, trying to find an expression which denotes the farthest logical connection from their current economic focus, in a sort of butterfly effect. In this way, the price of tea in China was used to denote the farthest possibility. It can also be used to denote an irrelevant topic.

In the United States, the phrase "What's that got to do with the price of eggs?" has been in use since the 1920s. The variance "of tea in China" seems to date from the 1940s and may be influenced by the idiom All the Tea in China. The British equivalent is "What's that got to do with the price of fish?" or "What's that got to do with the price of meat?". A Scottish variation is "What's that got to do with the price of cheese?", and a Northern Irish variation is "What's that got to do with the price of a sausage?".

There is also the derivative form of "what does that have to do with the price of rice in China," due to the common association between countries of Asia and rice. This variant was famously used in the 1976 film, Network.

There are about 35 ounces in one kilogram!