According to this common idiom, anything that costs “an arm and a leg” is very expensive.
Many claim to know where the phrase “an arm and a leg” came from. But what is the actual source of this strange idiom?
One incorrect source, part of a popular email titled “Little History Lesson” that spread like wildfire in 2000, claimed that something costing “an arm and a leg” comes from the days of George Washington. Some paintings, the email said, show Washington with an arm behind his back, and other paintings show all his limbs. The painters purportedly charged by the number of limbs in the painting.
But this story is false. While painters might charge for extra details or larger paintings, there is no evidence to suggest a per-limb fee.
The phrase only really shows up after WWII – way after Washington’s time. The earliest known source that phrases.org finds is from The Long Beach Independent in 1949: “Food Editor Beulah Karney has more than 10 ideas for the homemaker who wants to say ‘Merry Christmas’ and not have it cost her an arm and a leg.”
As part of the cost of WWII, many soldiers had lost limbs during the war. Perhaps these amputations created a dark influence over the English language.
Most likely, however, is the combination of two previous phrases from the 19th century: “I would give my right arm” and “If it takes a leg”.