To hit the sack is an informal idiom meaning to get into bed or go to sleep for the night.
Also: Sack out, hit the hay, hit the rack, turn in
Everyday Usage and Tone
Hit the sack is one of the most common conversational expressions used when wrapping up an evening or expressing exhaustion:
- Announcing Departure: Spoken when leaving a gathering or shutting down for the night (“I have an early flight tomorrow, so I’m going to hit the sack.”).
- Physical Fatigue: Emphasizing that someone is worn out and needs sleep immediately (“After twelve hours of yard work, I was ready to hit the sack at 8:00.”).
- Tone: Casual, friendly, and informal.
Origin & History of “Hit the Sack”
The idiom hit the sack originated in late 19th- and early 20th-century America and shares its exact historical roots with hit the hay:
The Hay-Filled Sack (The Shared Root)
Before modern spring, coil, and foam mattresses became standard household items, everyday bedding typically consisted of a coarse fabric ticking, literally a canvas, burlap, or cloth sack, stuffed with dried hay, straw, or corn husks. Because the physical mattress was a sack filled with hay, flopping down exhausted at the end of the day was described interchangeably as hitting the sack or hitting the hay.
The Idiomatic Sense of “Hit”
In 19th-century American slang, the verb hit began to be used not for striking an object with force, but to mean arriving at, engaging with, or setting out upon a destination (seen also in hit the road, hit the trail, or hit the books). Pairing hit with sack simply meant arriving at one’s bed with the immediate intention of falling asleep. It can also be seen as “using” or “engaging with” one’s bed.
World War II and “Sack Time”
While the verb phrase was already standard American vernacular by the early 1900s, military life during World War I and World War II cemented sack as universal slang for canvas bunks, cots, and sleeping bags. This wartime usage solidified hit the sack and gave rise to the noun phrase sack time (off-duty sleep), which returning veterans brought back into civilian workplaces nationwide.
Sentence Examples
- “It’s almost midnight and my eyes are burning—time to hit the sack.”
- “We have to be on the road by sunrise, so everyone should hit the sack early.”
- “He collapsed onto the couch at nine o’clock and said he was too tired to even make it upstairs to hit the sack.”
Similar and Related Expressions
- Sack Time: Time spent sleeping, resting, or off duty.
- Sack Out: A closely related phrasal verb meaning to fall asleep quickly, crash, or take a nap (e.g., “I’m just going to sack out on the couch for an hour.”).
- Hit the Hay: A virtually identical idiom with the same straw-mattress origin.
- Hit the Rack: Military and naval slang for going to bed (referring to stacked bunk beds).
- Turn In: A standard casual phrase for going to bed.
- Catch Some Zs: Informal slang for getting some sleep.