How much sleep have you lost?
Sleep debt accumulates and its effects are measurable long before you feel them.
Almost exactly a working week of short nights
10 h is more than 2 of the 5 references on this page.
Reference figures are measurements and are rounded; the unit conversion behind them is exact.
| Reference | Size | Yours ÷ theirs | Note |
|---|---|---|---|
| one short night | 2 h | 5× | Two hours lost |
| one night with no sleep | 8 h | 1.25× | |
| a working week of short nights | 10 h | 1× | Ten hours lost |
| two nights with no sleep | 16 h | 0.625× | |
| the record without sleep | 265 h | 1/26.5 | 11 days, Randy Gardner, 1964 |
Worth knowing
- After 17 to 19 hours awake, reaction times are comparable to a blood alcohol level of 0.05% — the drink-drive limit in much of the world.
- A week of six-hour nights produces cognitive impairment similar to one night with no sleep at all, and people consistently rate themselves as fine.
Frequently asked
Can you catch up on sleep?
Partly. One or two longer nights restore alertness and mood, but some measures of attention take a week to recover, and chronic debt is not fully repayable at weekends.
How long can a person stay awake?
The documented record is 11 days, set in 1964. Guinness stopped recognising attempts on safety grounds.
How to read this
This page describes measured effects; it is not medical advice.