Sleep
Who sleeps, how much, and when, from bats to hunter-gatherers to the American Time Use Survey.
Who's asleep right now?
At 3 a.m., about 95% of Americans are asleep. At noon, 4%.
Share of people 15+ asleep at each minute of the day (all days), from American Time Use Survey diaries, 2021–2025.
Show the data as a table
| Time | All days | Weekdays | Weekends & holidays |
|---|---|---|---|
| 00:00 | 86.5% | 87.0% | 85.3% |
| 01:00 | 92.5% | 92.8% | 92.0% |
| 02:00 | 94.8% | 94.9% | 94.6% |
| 03:00 | 95.3% | 95.3% | 95.2% |
| 04:00 | 91.8% | 91.0% | 93.9% |
| 05:00 | 85.0% | 82.5% | 90.7% |
| 06:00 | 66.8% | 61.2% | 80.0% |
| 07:00 | 43.4% | 36.2% | 60.2% |
| 08:00 | 24.6% | 19.6% | 36.5% |
| 09:00 | 13.7% | 11.1% | 19.7% |
| 10:00 | 7.2% | 6.3% | 9.3% |
| 11:00 | 4.7% | 4.3% | 5.6% |
| 12:00 | 3.6% | 3.4% | 3.9% |
| 13:00 | 4.1% | 3.9% | 4.5% |
| 14:00 | 4.6% | 4.3% | 5.2% |
| 15:00 | 4.4% | 4.0% | 5.2% |
| 16:00 | 4.0% | 3.7% | 4.8% |
| 17:00 | 3.2% | 2.9% | 3.7% |
| 18:00 | 2.8% | 2.6% | 3.2% |
| 19:00 | 3.6% | 3.5% | 3.8% |
| 20:00 | 7.3% | 7.2% | 7.5% |
| 21:00 | 20.2% | 20.1% | 20.4% |
| 22:00 | 46.3% | 46.7% | 45.2% |
| 23:00 | 72.3% | 72.9% | 70.7% |
Self-reported diary time coded as sleeping (includes naps and lying awake). Times bunch at the hour and half hour, which causes small steps.
Rankings
- RankingWhich animals sleep the least?Giraffes sleep 1.9 hours a day, the least of any mammal in the dataset.
- RankingWhich animals sleep the most?The little brown bat sleeps 19.9 hours a day, more than any other mammal on record.
- RankingWhich countries go to bed the latest?Oura Ring users in Russia fall asleep at 00:33 on weekdays, nearly two hours after South Africans (22:38).
- RankingWhich countries sleep the least?Oura Ring users in Japan sleep 6 h 6 min on weekday nights, almost an hour less than in New Zealand.
- RankingHow much do Americans sleep at each age?Americans sleep least in their early 40s (8.65 h a day) and most as teenagers (9.89 h).
- RankingWhich US states sleep the worst?In Hawaii 45.9% of adults sleep less than 7 hours a night, the highest share of any state.
Facts
- FactAmericans spend more time asleep than they did 20 years ago, not lessIn the American Time Use Survey, the average American aged 15+ spent 9.03 hours a day sleeping in 2025, up from 8.57 hours in 2003, about 28 minutes more. The rise was steady before the pandemic too (8.84 hours in 2019).Confidence: Solid
- FactThe bigger the mammal, the less it sleepsAcross 83 mammal species, every tenfold increase in body weight goes with about 21% less daily sleep (log-log slope −0.103, 95% CI −0.130 to −0.075, R² = 0.40). A 1 kg mammal is predicted to sleep about 10.1 hours; a giraffe actually logs 1.9.Confidence: Solid
- FactFatal car crashes rise 6% in the week after clocks spring forwardIn US crash data from 1996–2017, the risk of a fatal crash on the five workdays after the spring switch to Daylight Saving Time was 6% higher than in other weeks of the year (IRR 1.06, 95% CI 1.03–1.09). That is about 28 extra fatal crashes a year, or 627 over 22 years. The fall switch back showed no effect.Confidence: Single study
- FactFrigatebirds sleep in mid-air, about 40 minutes a dayGreat frigatebirds on flights of up to 10 days over the ocean slept 2.89% of the time (0.69 h, about 41 minutes, per day), sometimes with both brain hemispheres asleep at once. Back on the nest, they slept 53.28% of the time.Confidence: Single study
- FactPeople living without electricity don't sleep more than we doIn three pre-industrial societies with no electricity (the Hadza of Tanzania, the San of Namibia and the Tsimane of Bolivia), wrist actigraphy put average sleep at 5.7 to 7.1 hours a night across 10 recording groups (6.4 h on average), with sleep periods of 6.9 to 8.5 hours.Confidence: Debated
- FactFor over a century, experts have told kids to sleep about 37 minutes more than they doAcross 32 sets of children's sleep recommendations published from 1897 to 2009, recommended sleep exceeded children's actual sleep in 144 of 173 matched comparisons (83%), by 37 minutes on average. Recommendations fell by 0.71 min a year, almost exactly as fast as actual sleep (0.73 min a year).Confidence: Single study
- FactStarting school 55 minutes later gave Seattle teens 34 more minutes of sleepAfter Seattle moved high-school start time from 07:50 to 08:45, students' median wake-up on school days moved 44 minutes later and their median school-night sleep grew by 34 minutes, measured with wrist actigraphy.Confidence: Single study
- FactYour body clock runs latest at about 20In ~25,000 people, the midpoint of sleep on free days drifted later through adolescence and peaked at about age 20 (19.5 for women, 20.9 for men) before moving steadily earlier for the rest of life.Confidence: Solid
- FactUS melatonin use rose about fivefold in two decadesThe share of US adults who reported taking melatonin in the past 30 days rose from 0.4% in 1999–2000 to 2.1% in 2017–2018, with almost all of the rise after 2009–2010.Confidence: Solid
- FactThere's no clear evidence that adults sleep less than 50 years agoA meta-analysis of 168 studies (257 data points, 6,052 healthy adults aged 18–88) that measured sleep objectively between 1960 and 2013 found no significant link between the year of a study and how long people slept. Reviews of self-reported sleep are mixed, though, and some large surveys do show a decline.Confidence: Debated
- FactWild elephants sleep about 2 hours a dayTwo wild African elephant matriarchs tracked for about five weeks slept an average of 2.0 hours a day (2.3 h and 1.8 h), mostly between 02:00 and 06:00, and sometimes went about 46 hours without sleeping.Confidence: Single study
Datasets
- DatasetWhen and how long Americans sleep (American Time Use Survey)Share of Americans asleep at each minute of the day, average sleep by age, and the 2003–2025 trend, computed from BLS ATUS time-diary microdata.American Time Use Survey 2003–2025, U.S. Bureau of Labor Statistics
- DatasetSleep in mammalsDaily total and REM sleep, sleep-cycle length, brain and body weight for 83 mammal species, from Savage & West (2007) via ggplot2's msleep.Savage & West (2007), PNAS
- DatasetWhen the world falls asleep, wakes up, and how long it sleepsMean sleep onset, wake time and total sleep for 35 countries, measured by the Oura Ring over 50 million nights in 2021 (Willoughby et al. 2023).Willoughby et al. (2023), Sleep Medicine
- DatasetShort sleep in the United States by state and countyShare of US adults sleeping under 7 hours per 24 h, by state (BRFSS 2022, age-adjusted, 95% CI) and by county (CDC PLACES 2025 model-based).CDC BRFSS 2022 via U.S. Chronic Disease Indicators (SLP03)
About these numbers
Every number on these pages comes from a primary source: a government survey, a peer-reviewed paper or its supplementary data. Each fact carries a confidence label, the sample size, and a link to where the number was found. The datasets behind the rankings can be downloaded as CSV or JSON.