How long is a piece of string?

idiom

Used to suggest that there's no definite or answerable question about something, or it varies greatly.

How much longer will we have to wait? How long is a piece of string? I don't know the answer.

Often appears as...

how much does it cost - how long is a piece of string?

can you tell me - how long is a piece of string?

Usage tips

Informal

Idiomatic

Definition 1 of 1

Pro Tip 1/3

Uncertainty Context

Use when an exact number or amount cannot easily be given or is unknown. Slide

Slide

How long will the meeting last? Well, how long is a piece of string?

Pro Tip 2/3

Non-literal Use

Understand it's a rhetorical question, not expecting a literal answer about string. Slide

Slide

How successful will the project be? That's like asking how long is a piece of string.

Pro Tip 3/3

Avoid Overuse

Use sparingly to avoid vagueness in situations where specifics are important. Slide

Slide

When budgeting, instead of asking 'How long is a piece of string?', seek exact figures.