Idiom B1

Cost an arm and a leg

Be very expensive

Meaning

Cost an arm and a leg — To be extremely expensive; to cost a very large amount of money.

Origin & History

The phrase appeared in American English during the 20th century. One theory connects it to portrait painters who charged more when limbs were included. Another links it to the very high price soldiers 'paid' by losing limbs in war.

Example Sentences

SentenceContext
That handbag costs an arm and a leg — I can't afford it.Personal shopping
Flights during the holidays cost an arm and a leg.Travel expense
Good healthcare in some countries can cost an arm and a leg.Social commentary

How to Use It

Informal. Common in everyday speech and casual writing. Avoid in formal financial or business documents.

Common Mistakes

Mistakes to Avoid

It cost an arm and leg to renovate the kitchen.

It cost an arm and a leg to renovate the kitchen. — Both articles are required: 'an arm AND A leg'.

The concert tickets costed an arm and a leg.

The concert tickets cost an arm and a leg. — 'Cost' is irregular; past tense is also 'cost', not 'costed'.

Similar Idioms

Break the bankHighway robberyCost a pretty penny All Idioms →

Practise This Idiom

Flip Tiles Flash Cards

Practice English Idioms

Use these exercises to master idioms in context:

Flip Tiles Find the Match Idioms Quiz

Frequently Asked Questions

What does "Cost an arm and a leg" mean?
"Cost an arm and a leg" means be very expensive. To be extremely expensive; to cost a very large amount of money.
Where does the idiom "Cost an arm and a leg" come from?
The phrase appeared in American English during the 20th century. One theory connects it to portrait painters who charged more when limbs were included. Another links it to the very high price soldiers 'paid' by losing limbs in war.
Can you give an example of "Cost an arm and a leg" in a sentence?
Here is an example: "That handbag costs an arm and a leg — I can't afford it." — used when personal shopping.
Is "Cost an arm and a leg" formal or informal?
Informal. Common in everyday speech and casual writing. Avoid in formal financial or business documents.
What CEFR level is "Cost an arm and a leg"?
This idiom is typically taught at B1 level. It is a intermediate expression that appears in a wide range of spoken and written English contexts.
What are common mistakes with "Cost an arm and a leg"?
The most common mistake is getting the articles wrong. Always use the fixed form of the idiom without changing the words. For example: It cost an arm and a leg to renovate the kitchen. — Both articles are required: 'an arm AND A leg'.
What idioms are similar to "Cost an arm and a leg"?
Similar idioms include: Break the bank, Highway robbery, Cost a pretty penny. These share the same general meaning but may differ slightly in tone or context.
How do I practise idioms like "Cost an arm and a leg"?
LexFizz's Flip Tiles and Flash Cards exercises are great for practising English idioms. Try to write your own example sentences using the idiom in context, and listen for it in films, podcasts, and conversations.
Can "Cost an arm and a leg" be used in writing?
Yes, but it depends on the register. Informal. Common in everyday speech and casual writing. Avoid in formal financial or business documents. Idioms generally work best in spoken English or informal writing; avoid them in formal academic or professional documents unless you are sure of your audience.
Does "Cost an arm and a leg" have the same meaning in British and American English?
Yes, "Cost an arm and a leg" is understood in both British and American English with the same meaning: be very expensive. Some idioms vary between dialects, but this one is widely recognised in all major varieties of English.