Cost an arm and a leg: meaning, examples and when to use it
Short answer: “Cost an arm and a leg” means to cost a lot of money. You say it about something very expensive: “That watch costs an arm and a leg.”
What does “Cost an arm and a leg” mean in English?
An arm and a leg are very important parts of a body, so the idiom says that the price is very high. No one loses anything. It is a strong way to say “very expensive”.
Examples of “Cost an arm and a leg”
- A big city apartment can cost an arm and a leg.
A high price for a home. - Those new shoes cost me an arm and a leg.
You can add the person who pays: cost me, cost us. - Concert tickets cost an arm and a leg this year.
A high price for an event.
When do you use “Cost an arm and a leg”?
- To complain about a high price.
- To explain why you will not buy something.
- In speech and casual writing.
Is “Cost an arm and a leg” formal?
“Cost an arm and a leg” is informal. It is fine with friends and in casual writing. In a formal text, write “very expensive”.
Common mistakes with “Cost an arm and a leg”
- It is only about price. Nobody is hurt.
- Keep the order: “an arm and a leg”, not “a leg and an arm”.
- Use “cost”, not “spend”. You spend money, but a thing costs an arm and a leg.
Similar expressions
- The opposite is “a dime a dozen” (very common, not special). See idioms about money.
Questions
What does “Cost an arm and a leg” mean in English?
“Cost an arm and a leg” means to cost a lot of money. You say it about something very expensive: “That watch costs an arm and a leg.”
Is “Cost an arm and a leg” formal?
“Cost an arm and a leg” is informal. It is fine with friends and in casual writing. In a formal text, write “very expensive”.
Does “cost an arm and a leg” mean it is dangerous?
No. It only means that something costs a lot of money.
What is the opposite?
You can say that something is cheap, or “a dime a dozen” when something is very common.
Part of the English idioms guide and of idioms about money, in the 💬 Idioms tool. Đọc bằng tiếng Việt.
Written for English learners by the English for Fun team. How we write our lessons · Last updated 2026-11-05.