Hit the sack
/hɪt ðə sæk/informalUS · UK · AU · CA · IE
What does “Hit the sack” mean?
Hit the sack means to go to bed in order to sleep.
To hit the sack simply means to go to bed. People use it late at night when they feel tired and want to sleep.
This expression is casual and friendly. It is common among friends and family, but you should avoid using it in formal writing or professional meetings.
When do people say it?
People usually say this late in the evening when they feel tired and are ready to sleep.
“I have an early start tomorrow, so I am going to hit the sack now.”
Is it formal or informal?
Register: informal. It is most at home in everyday conversation rather than formal writing. Most common in US and UK and AU and CA and IE.
Where does it come from?
In the past, simple mattresses were cloth sacks filled with straw or feathers. Because of this, the word 'sack' became a common slang term for a bed.
Origin confidence: Well documented
How do you say “Hit the sack” in other languages?
Last reviewed 2026-09-11