How Much Sleep Do Teens and Students Need in the Week Before an Exam?

This is general information, not medical advice. If you have a sleep problem or a health condition, talk to a doctor.

With exams close, the most tempting trade is also the most common one: cut sleep, gain study time. For HSC, VCE, GCSE, SAT, ACT and university finals students alike, the question is whether that trade is worth it. Here is what the health guidelines and the research actually say.

How many hours do you need?

Two widely cited sources give similar ranges:

• The American Academy of Sleep Medicine (AASM) consensus statement recommends that teens aged 13 to 18 get 8 to 10 hours of sleep in each 24-hour period, on a regular basis. It links regularly sleeping less than that with attention and learning problems, and sleeping the recommended amount with better attention, learning and memory.
• The CDC lists 8 to 10 hours for ages 13 to 17 and 7 or more hours for adults aged 18 to 60.

The UK's NHS gives the same teen range for exam time and adds that cramming all night before an exam is usually a bad idea.

These are population guidelines, not a personal prescription. Some people need a little more or less, and a guideline cannot tell you how many hours will suit you on a given night.

Why sleep matters for what you just studied

The US National Institute of Neurological Disorders and Stroke (NINDS) explains that without sleep you cannot form or maintain the brain pathways that let you learn and create new memories, and that lack of sleep makes it harder to concentrate and respond quickly. It also says memory consolidation most likely requires both non-REM and REM sleep.

A review in Nature Reviews Neuroscience describes sleep as a state that optimizes the consolidation of newly acquired information, with slow-wave sleep and REM sleep playing different roles. An earlier review in Neuron collected evidence for sleep-dependent memory processing, while also discussing unanswered questions and arguments against a role for sleep in learning.

What this means in practice: sleep is not wasted study time. It is part of how studying turns into something you can recall. What the research does not give us is a number such as "one extra hour of sleep equals so many marks". Be wary of anyone who offers one.

Sleep or one more hour of studying?

A research team studied 535 students in grades 9, 10 and 12 at three Los Angeles-area high schools. For 14 days in each year, students kept diaries of how long they studied, how long they slept, and whether they had two kinds of academic problem: not understanding something taught in class, or doing poorly on a test, quiz or homework.

According to the researchers' summary, students who gave up sleep to study more than usual were more likely to report academic problems the next day, regardless of how much they usually studied. In the researchers' interpretation, the reduced sleep was what accounted for the increase, but because this was an observational diary study, it shows an association rather than established cause. The senior author also stressed that nobody was suggesting students should not study. Students who studied more overall tended to earn higher grades.

This was a diary study, so it shows an association rather than proving cause. But it matches the guidance above: the problem is not studying, it is where the study hours come from.

A practical plan for the week before the exam

These are practical suggestions based on the guidelines above, not clinical advice.

1. Work backwards from your wake-up time. If you must be up at 6:30 and aim for 8 hours, lights out is around 10:30 pm. Plan revision to end earlier than that.
2. Keep the schedule steady. Aim for similar bed and wake times each day so exam week does not add extra shifts to your body clock. This is a common-sense suggestion rather than a finding from the sources below.
3. Wind down. The NHS suggests allowing around half an hour between studying, screens and bed.
4. Do not make the last night a test of willpower. If you slept normally all week, one restless night is unlikely to undo your preparation. This is common-sense reassurance, not a finding from the sources above.
5. Plan revision inside the hours that are left. If the timetable does not fit, shorten the list of topics rather than the night.

Key takeaways

• Teens: 8 to 10 hours per 24 hours (AASM; CDC for ages 13 to 17). Adults 18 to 60: 7 or more hours (CDC).
• Sleep supports memory consolidation, but no source we found supports a promised score improvement.
• Giving up sleep for extra study time was linked to more next-day academic problems in one large diary study.
• Ask for help if you have persistent trouble sleeping.

For what to do after a bad night, see our guide on how to function after a sleepless night, and for structuring a final week, see Monk Mode Exam Week. If you are choosing between a short sleep and staying up, our article on 2 hours of sleep vs an all-nighter covers the trade-off.

Sources

• CDC: About Sleep - recommended hours for teens (13 to 17) and adults (18 to 60).
• AASM consensus statement: Recommended Amount of Sleep for Pediatric Populations (JCSM) - 8 to 10 hours for ages 13 to 18 and the associations with attention, learning and memory.
• NINDS: Brain Basics, Understanding Sleep - sleep, learning and memory consolidation.
• Diekelmann and Born, The memory function of sleep (Nature Reviews Neuroscience, 2010) - review abstract.
• Walker and Stickgold, Sleep-dependent learning and memory consolidation (Neuron, 2004) - review abstract.
• UCLA Health: Cramming for a test? Don't do it, say UCLA researchers - diary study of 535 high school students (Child Development, 2013; online 2012).
• Gillen-O'Neel, Huynh and Fuligni, To study or to sleep? The academic costs of extra studying at the expense of sleep (Child Development, 2013) - 535 students, 14-day diaries.
• NHS: Help your child beat exam stress - teen sleep range, wind-down time, cramming all night.