Asked by: Martin Moore, Glasgow
The cliché is that we need eight hours a night, but the actual answer to this question is more complicated. Our sleep requirements change throughout life. Guidelines proposed by the National Sleep Foundation in 2015 recommended that newborns have 14 to 17 hours per night, teenagers have 8 to 10 hours, and adults have 7 to 9 hours. These guidelines focus largely on ‘average’ requirements, but individuals can differ greatly from one another. For example, it may be appropriate for certain teenagers to have as few as 7 hours per night, or as many as 11. If you’re not functioning your best, it’s worth considering whether you’re getting enough sleep.
Subscribe to BBC Focus magazine for fascinating new Q&As every month and follow @sciencefocusQA on Twitter for your daily dose of fun science facts.