Hit the sack is a friendly, sleepy idiom. It means to go to bed. The sack here is an old slang word for a bed, so the phrase paints a picture of falling into bed at the end of a long day.
It is common in American English and understood everywhere. People use it at the end of an evening, before a long journey or after a hard day of work.
This page explains the meaning, the grammar, the register and the close alternatives. The 10-question drill at the end explains each answer.
What it means
In one sentence: To hit the sack means to go to bed and settle down to sleep, especially when you are very tired.
What the idiom means in everyday English
- It means going to bed, not just feeling sleepy: "I am going to hit the sack."
- The idiom usually suggests real tiredness at the end of a long day.
- It is often used in first-person plans: "I will hit the sack early tonight."
- You can use it for other people: "The children hit the sack at eight."
How the idiom behaves in a sentence
- The fixed pattern is hit the sack: "It is late; I am going to hit the sack."
- The verb hit stays hit in the past, never hitted: "He hit the sack at nine."
- Common patterns are going to hit the sack, time to hit the sack and hit the sack early.
- The phrase almost always keeps the article the and the singular sack.
When the idiom does not fit
- It is not the same as falling asleep by accident. Hit the sack is a deliberate plan to go to bed.
- Avoid it in formal writing. Write "go to bed" or "retire for the night".
- It can sound too casual in a work email, especially to a senior colleague.
- Do not confuse it with hit the books, which means to study, or hit the road, which means to leave.
Where it comes from
Sack has meant a bed in informal English since the 1800s, when a bed could be a simple sack of straw. The phrase hit the sack is recorded in American English from the early 1900s. The exact first writer is not known, but the slang sense of sack is well recorded.
Use it or not
Register: Very informal. Hit the sack belongs in conversation with friends and family, in messages and in casual writing. It is common in American English. In a work email or a formal text, use "go to bed" or "turn in". The phrase is warm and playful, never rude.
Examples
- I have an early start tomorrow, so I am going to hit the sack.The reason for going to bed comes first.
- The children hit the sack as soon as the film ended.The past form is hit, not hitted.
- It is time to hit the sack; we have a long drive in the morning.Time to introduces the plan to sleep.
- He was so tired that he hit the sack before dinner.The idiom can describe going to bed unusually early.
- I usually hit the sack around eleven.The phrase can describe a habit.
- Come on, kids. Hit the sack; school starts early.An informal instruction to children.
- We hit the sack at midnight and slept for nine hours.The past form works with a time phrase.
Similar idioms
hit the hay
to go to bed, with the same informal feeling.
turn in
to go to bed, slightly more polite than hit the sack.
call it a night
to stop an evening activity and go to bed.
go to bed
the neutral, safe phrase for any situation.
crash
to fall asleep quickly, very informal.
Practice drill
Answer all 10 questions. Each answer is marked at once, and the meaning is explained under the question.
It is almost midnight and I am very tired. I am going to ___.
Show answer and explanation
Answer: A. hit the sack Hit the sack means to go to bed, which is what a tired person does at midnight.
Which sentence uses hit the sack correctly?
Show answer and explanation
Answer: B. I hit the sack at ten and slept until seven. Hit the sack means to go to bed, so the sentence about sleeping from ten until seven is correct.
What does hit the sack mean?
Show answer and explanation
Answer: C. to go to bed Hit the sack is an informal way to say go to bed; sack is old slang for a bed.
The children are tired after the party. What do the parents say?
Show answer and explanation
Answer: D. Time to hit the sack, kids. Hit the sack means go to bed, and tired children after a party need sleep.
What is a sack in this idiom?
Show answer and explanation
Answer: A. an old informal word for a bed In the idiom, sack is old slang for a bed, which is why hit the sack means to go to bed.
Choose the sentence with the same meaning: "He hit the sack at nine."
Show answer and explanation
Answer: B. He went to bed at nine. Hit the sack means to go to bed, so the sentence means he went to bed at nine.
Which is correct?
Show answer and explanation
Answer: C. I am going to hit the sack. The fixed phrase keeps the article the and the singular sack: hit the sack.
Why might someone hit the sack early?
Show answer and explanation
Answer: D. because they are very tired Hit the sack means to go to bed, so being very tired is the natural reason to do it early.
Which sentence does NOT use hit the sack correctly?
Show answer and explanation
Answer: A. Please hit the sack if the delivery arrives. The idiom means going to bed, not hitting a bag or a parcel, so the delivery sentence is wrong.
A friend says, "I am going to hit the sack." What does the friend mean?
Show answer and explanation
Answer: B. They are going to sleep. Hit the sack means to go to bed, so the friend is going to sleep.
Questions learners ask
Is hit the sack formal or informal?
It is very informal. It is perfect for friends and family, in messages and in light writing. For work or formal writing, say "go to bed", "turn in" or "retire for the night".
What is the past tense of hit the sack?
The past tense is hit: "I hit the sack at ten." English does not use hitted. The time phrase tells you whether the sentence is about now or the past.
Does hit the sack mean to sleep immediately?
It means to go to bed with the intention of sleeping, usually because you are tired. The actual sleep may take a few minutes, but the idiom describes the moment of getting into bed.
More idioms
Ring a bell
If a name, a face or a story rings a bell, it sounds familiar, even if you cannot remember where you know it from.
On cloud nine
To be on cloud nine is to be extremely happy, often because something wonderful has just happened.
Spill the beans
To spill the beans is to tell a secret, usually before you are supposed to or without meaning to.
Browse all the idiom pages or take the free A1 to C2 level test to find your starting point.