How much sleep do I actually need?

The number you have heard is eight hours. It is the most recited figure in popular sleep advice, and it is one of the least useful things to take personally. The expert consensus is that adults should aim for seven to nine hours, with older adults seven to eight, but this is a range and individual need within it varies considerably. Some people thrive on six and a half hours. Others need close to nine. The more useful question is not how many hours but how restored you feel, how steady your attention through the day, and whether the pattern itself is stable.

Written and reviewed by Natalia Cajide, Registered Psychologist (AHPRA PSY0002474316). 4 min read. Published 7 June 2026. Last reviewed 7 June 2026. Next review 7 June 2027.

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Where the eight-hour figure came from

The "eight hours" line is everywhere, and it sounds precise enough that most people treat it as a personal target. It is not. It is a population average dressed up as a number. The expert consensus, based on a comprehensive review of the literature, is that adults should aim for seven to nine hours, with older adults seven to eight (Hirshkowitz et al., 2015). The recommendation is a range, not a single figure, and the panel that produced it was explicit that some healthy adults sleep well outside this range. The range is a useful population guide. It does not predict any particular person's need.

When I find that someone has internalised "eight hours" as the standard they are failing, the first work is often loosening the grip of that number. The body does not check whether it slept eight hours. The body checks whether the sleep it had was enough for the work the next day will ask of it.

What the population data actually shows

When researchers look at sleep duration and health outcomes across large populations, the relationship is a curve, not a straight line. A 2017 meta-analysis of prospective cohort studies (Yin et al.) found a U-shaped pattern for all-cause mortality, with the lowest risk around seven hours. Both significantly less and significantly more were associated with worse outcomes. The shape of the curve is consistent across studies. More is not better past a certain point. Less, sustained over time, carries cost.

But the population average is not a personal prescription. Within any given person, sleep need is shaped by genetics, age, life stage, and what the day asks of the body. The mortality curve is one input. It is not the whole picture, and it is not designed to be applied as a personal target.

A more useful question to ask

I find that the chase for a specific number often creates the kind of anxiety that interferes with the sleep it is meant to optimise. A person wakes at 6am after six and a half hours, feeling reasonably alright, then checks the clock, realises they "should have" slept longer, and the day starts on a worry. The worry adds nothing to the sleep that has already happened. It just sits on top of the day.

A more useful set of questions might be these. Do you wake feeling reasonably restored most of the time. Can you maintain attention and mood through the day without escalating caffeine. Is your sleep pattern stable from night to night. These are functional questions, and the answers tell you more about whether your sleep is working for you than any single number can.

The number is not nothing. But it is a range, set against your particular biology, and it lives downstream of the things that actually shape it. The amount of sleep you genuinely need is, in the most honest sense, the amount your body is asking for. Whether you are giving it that, and what is getting in the way if you are not, are more useful questions than whether you are hitting an external target. The most important shift, when sleep is worrying you, is often not from too little sleep to more sleep. It is from measuring your sleep against a population number to noticing what your body is actually doing with the sleep it gets. That noticing is the beginning of a different kind of conversation about sleep, and it is one that respects the specificity of who you are rather than asking you to conform to a generalisation that was never meant to apply to anyone in particular.

This content is general information only. It is not a substitute for individual psychological or medical advice. Reading this does not establish a therapeutic relationship with Equal Psychology or any of their clinicians.