How long is a piece of string?

Example in use: “He wanted me to tell him how long it was going to take to finish the project. So I asked him, “How long’s a piece of string?””

Meaning: Used to answer a question where the answer is unknown as the length of “a” piece of string could be anything at all but who could possibly know for sure?

Possible German equivalent: Wie tief ist das Meer?

Possible origin: As much as I looked around, I could find no origin at all for this idiom and we just have to assume that it is merely a riddle type expression that developed as a way to answer something that is unknowable. However, if someone thinks they are smart and responds to something you ask them “How long’s a piece of string?” the clever answer is to say “Twice as long as half its length.” Perfectly logical of course!

string / strɪŋ


Welcome again to our weekly series that hopes to go behind the scenes of some rather typical English expressions.