I get this question a lot from my students. Someone hears a native speaker say something “cost an arm and a leg” and instantly thinks, wait… HUH?

This is a very common English idiom, and once you understand it, you will hear it everywhere. People use it when talking about rent, travel, phones, weddings, and pretty much anything that hurts the wallet.

In this guide, I break down what “cost an arm and a leg” really means, why people say it, and how to use it naturally in daily English without sounding strange or too dramatic.

What is the Meaning of the Idiom Cost An Arm and a Leg?

“Cost an arm and a leg” means something is very expensive. People use it when the price feels shocking, painful, or just plain unfair.

It does not mean you actually give up your arm or leg. It is a dramatic way to say the price is extremely high. English loves drama. This idiom is all about feeling, not maths.

When someone says this phrase, they are usually reacting to the price. They might be surprised, annoyed, or stressed about how much something costs.

It often carries the idea of “that is way too much for me.”

You can use it for almost anything that feels overpriced. Rent, flights, phones, weddings, medical bills, or a dinner that looked small but emptied your wallet.

Grammatically, it is easy to use. You just change the verb, not the phrase itself.
“That jacket costs an arm and a leg.”
“That jacket cost an arm and a leg.”
“That jacket is going to cost an arm and a leg.”

If you want, we can move straight into why people say this phrase next and keep the same clean style.

Why Do We Say Cost an Arm and a Leg?

Honestly, because it sounds painful. And that is exactly the point.

When something is very expensive, it can feel like you are giving up something important just to pay for it. Not money only. Comfort. Savings. Peace of mind. Your soul, maybe.

English speakers like strong images. Saying “it’s very expensive” is boring. Saying “it cost an arm and a leg” makes people instantly understand how bad the price feels.

It also adds emotion. You are not just sharing information. You are sharing your reaction. You are basically saying, “I paid for this, and I am still upset about it.”

People often use this phrase when:

• they regret buying something
• they want to complain a little
• they want to warn a friend
• they want sympathy

It is the kind of phrase you hear in real conversations, not textbooks. Someone buys concert tickets, checks their bank app, and says, “Yeah… it cost an arm and a leg.”

How Do You Use the Idiom “An Arm and a Leg” in a Sentence?

This is one of the those easy English phrases to use, which is why learners like it. You usually use it after the price is mentioned or understood.

Most of the time, it comes after the thing you are talking about.

You talk about the thing first, then you say it cost an arm and a leg.

You can use it when:

• talking about something you bought
• explaining why you did not buy something
• warning a friend about prices
• complaining in a casual way

You normally use it with verbs like:

• cost
• costs
• cost me
• is going to cost

It almost always talks about money, not time or effort. So you would not use it for “that homework cost me an arm and a leg in time.” That sounds wrong.

Tone matters too. This idiom is informal and conversational. It fits chats with friends, family, or colleagues you know well. It does not fit formal writing, contracts, or serious reports. Save it for real-life talk.

Also, you usually say it after the fact. You bought the thing, you saw the bill, then you complain. Very human behaviour.

Examples Using “An Arm and a Leg”

You will hear this idiom a lot in everyday English, especially when people talk about money. These examples show how native speakers use it naturally when they feel something is too expensive.

• That hotel in Bali cost an arm and a leg, but the view was amazing.
  Meaning: The hotel was very expensive.
• My phone repair cost an arm and a leg, and it was broken again a week later.
  Meaning: Fixing the phone was expensive and not worth the money.
• We wanted to fly last minute, but the tickets cost an arm and a leg.
  Meaning: The flight tickets were extremely expensive.
• Her wedding dress cost an arm and a leg, and she only wore it once.
  Meaning: The dress was very expensive for something used one time.
• Renting an apartment in the city centre costs an arm and a leg now.
  Meaning: Rent in that area is very high.
• I loved the concert, but the tickets cost an arm and a leg.
  Meaning: The tickets were too expensive.
• The dentist said it would cost an arm and a leg, so I said I would think about it.
  Meaning: The dental treatment was very costly.
• That tiny cup of coffee cost an arm and a leg for no reason.
  Meaning: The coffee was overpriced.
• Buying a car right now costs an arm and a leg.
  Meaning: Cars are very expensive at the moment.
• He wanted to join the gym, but the membership cost an arm and a leg.
  Meaning: The gym fee was too expensive.

These sentences all sound natural in casual conversations. If you can use this idiom like this, you already sound much more like a native speaker.

Common Beginner Mistakes With This Idiom

This idiom is easy, but learners still make a few common mistakes. Let’s clean those up now so you sound natural, not awkward.

One big mistake is using it too literally. Some learners joke about real arms and legs in serious conversations. Native speakers do not do that. The phrase is normal, not funny by itself.

Another mistake is using it in very formal situations. You would not use this idiom in a business contract, a formal email, or an exam essay. It is for speaking and casual writing only.

Some learners also change the words inside the idiom. You should not say “cost a leg and an arm” or “cost my arm and leg.” The phrase stays the same: an arm and a leg.

A very common error is using it for time or effort instead of money. This idiom is about price. Saying “that project cost an arm and a leg in time” sounds wrong to native speakers.

Another mistake is overusing it. If everything costs an arm and a leg, the phrase loses its power. Use it when something is truly expensive, not just a little pricey.

If you avoid these mistakes, you will sound relaxed and natural when you use this idiom.

Similar English Idioms That Mean “Expensive”

English has a lot of idioms for expensive things. Some sound funny. Some sound dramatic. All of these are real idioms, not normal phrases.

These are the most common ones you will actually hear.

• Cost a fortune
  Meaning: Very expensive. Often used when something costs more than expected.
• Cost the earth
  Meaning: Extremely expensive. Mostly British English.
• Cost a bomb
  Meaning: Very expensive. Casual British slang.
• Break the bank
  Meaning: So expensive it uses all your money.
• Be priced through the roof
  Meaning: Prices are extremely high.
• Cost the shirt off your back
  Meaning: So expensive you are left with nothing.
• Be worth its weight in gold
  Meaning: Very valuable or expensive, often in a positive way.

All of these funny English idioms are informal and used in conversation. You would not normally use them in formal writing, but they sound very natural when speaking with friends.

Other Ways to Say Something is Expensive

Sometimes you do not need an idiom. You just want to be clear and simple. These phrases are very common and safe to use in everyday English.

• It’s expensive
  Simple, direct, and always correct.
• It’s really expensive
  A stronger version of “expensive.”
• It’s overpriced
  Used when you think the price is unfair.
• It costs a lot
  Very natural for speaking.
• It’s not cheap
  A softer, more polite way to say it is expensive.
• It’s way too expensive
  Shows strong feeling or frustration.
• That price is ridiculous!
  Very emotional and casual. Used when you are shocked or annoyed.
• That’s way too pricey
  Casual and conversational. Common in everyday speech.
• It’s premium pricing
  Sounds more neutral and slightly professional. Often used in marketing or sales talk.
• No way I’m paying that kind of money!
  Strong and very informal. Clear refusal.
• The price is on the higher end of the spectrum
  More polite and formal. Good for work or professional situations.
• It’s out of my budget
  Polite and useful in shops, travel, or business talks.
• It’s way more than I expected
  Calm and non-confrontational.

These options let you adjust your tone. You can sound angry, casual, polite, or professional, all without using an idiom.

Cost an Arm and a Leg Origin

The short answer is this. No one knows the exact origin for sure. There is no single moment where this phrase was officially born. Very English, honestly.

One popular idea comes from old wars. Soldiers sometimes lost arms or legs in battle, and those injuries were seen as the highest possible price to pay.

Over time, people started using the idea of losing a body part to describe something that costs a lot.

Another theory comes from early art and portrait painting. In the past, artists charged more money if a painting showed a person’s arms and legs.

A full-body portrait cost much more than a face-only painting. So if you wanted arms and legs included, it would cost you more.

There is also a simpler explanation. English speakers like exaggeration. Losing an arm and a leg sounds extreme, so it became a strong way to describe extreme prices.

What matters most is not which story is true. What matters is how the phrase is used today. Native speakers do not think about the origin when they say it. They just use it to mean “very expensive.”

Should You Use This Phrase in Daily English?

Yes, you can. And you probably should.

“Cost an arm and a leg” is very common in daily English. Native speakers use it all the time when talking about prices, especially when complaining or warning a friend.

It works best in casual situations. Talking with friends, family, classmates, or colleagues you know well. It sounds natural and relaxed in conversation.

You should not use it in very formal situations. Do not put it in contracts, serious business emails, or academic writing. In those cases, stick to simple phrases like “very expensive” or “high cost.”

If you want to sound natural but not dramatic, use it once in a while. Overusing it can make you sound like everything hurts your wallet.

If you use it the way native speakers do, it is a great phrase to have in your everyday English.

FAQs About an Arm and A Leg