Is 7.5 hours of sleep better than 8?

The amount of sleep each person needs varies, but experts generally recommend adults get between 7 and 9 hours of sleep per night. Many people aim for 8 hours of sleep as this is often touted as the “ideal” amount, but some find that 7.5 hours works better for them. So is 7.5 hours of sleep actually better than 8 hours for some individuals? There are several factors to consider.

Quick Overview

The quick answers to whether 7.5 hours of sleep is better than 8 hours:

  • Most adults need 7-9 hours of sleep per night.
  • The right amount of sleep is individual – some do better with 7.5 hours versus 8 hours.
  • Quality of sleep is just as important as quantity.
  • 7.5 hours may be better if you have no problem waking up and feel well-rested.
  • 8 hours may be better if you still feel tired after 7.5 hours.
  • Listen to your body’s signals and tailor your sleep duration. Experiment to find your optimal amount.

Factors That Influence Sleep Needs

There are several factors that determine how much sleep an individual needs:


Younger adults tend to need more sleep. Newborns need 14-17 hours of sleep per day, school-age children need 9-11 hours, teens 8-10 hours, and adults 7-9 hours. As we get older, our sleep needs decrease. Older adults may feel well-rested on just 6-8 hours of sleep.

Individual Differences

Genetics play a role in our sleep needs. Some people are just fine on less sleep, while others require more. Women often need a bit more sleep than men.


If you have any medical conditions, medications, or other health factors impacting your sleep, this may increase your sleep needs. Things like chronic pain, anxiety, depression, and sleep disorders can all make it harder to get quality sleep.

Activity Level

If you have an active job or exercise regularly, your body uses sleep to repair muscles and refuel. Those with more active lifestyles often require more sleep.

Quality of Sleep

Getting uninterrupted, deep sleep allows you to fully recharge in less time. If you have poor quality sleep marked by wakings or little time in deep sleep stages, you’ll likely need to spend more time asleep.

So in considering 7.5 hours versus 8 hours, the quality of your sleep and individual factors are important.

Pros and Cons of 7.5 Hours of Sleep

Here’s a look at some of the main pros and cons of getting 7.5 hours of shut-eye:


  • More free time – Getting 7.5 hours means 30 more minutes of time for other activities.
  • May prevent grogginess – Some people feel groggy if they oversleep.
  • Sufficient for many – 7.5 hours is plenty for a lot of adults.
  • May help regulate sleep cycle – Waking at the ideal time in your sleep cycle results in less grogginess.


  • Increased fatigue – For some, 7.5 hours leaves them feeling tired during the day.
  • Hormone issues – Long term sleep debt can disrupt hormone production.
  • Higher obesity risk – Those who regularly get insufficient sleep are more likely to develop obesity.
  • Decreased performance – Too little sleep can hinder memory, productivity, and focus.
  • More safety risks – Insufficient sleep increases the chances of errors and accidents.

Whether 7.5 hours is enough comes down to the individual. Pay attention to how you feel on this amount of rest. If you don’t experience daytime fatigue, have trouble concentrating, or feel productive, then 7.5 hours may suit your needs. But if you have signs of sleep deprivation, you may require more time asleep.

Pros and Cons of 8 Hours of Sleep

What about the benefits and drawbacks of getting a full 8 hours of sleep?


  • Less fatigue – Most people feel more alert, focused, and energized after 8 hours.
  • Better memory – More sleep is linked to improved learning, concentration, and recall.
  • Decreased risk of health issues – 8 hours may lower the chances of obesity, heart disease, diabetes, and stroke.
  • Less stress and anxiety – Adequate sleep regulates mood and helps Manage stress.
  • Injury prevention – Being well-rested lowers accident risk.
  • Overall wellness – Long term, 8 hours per night benefits overall health.


  • Less free time – 30 minutes less for other wakeful activities.
  • Potential for grogginess – Some people feel tired if they oversleep.
  • Disrupted sleep cycles – Waking up at the wrong time can make you feel groggy.

As you can see, most of the research points to 8 hours of being ideal for the average, healthy adult. But some people function fine on slightly less sleep.

Tips for Deciding What’s Best

Here are some tips for figuring out your perfect sleep duration:

  • Track your sleep – Use a sleep tracking app and log your hours slept and quality.
  • Note how you feel – Pay attention to energy, mood, focus, and productivity.
  • Experiment – Try 7.5 hours for a week, then try 8. See when you feel your best.
  • Check for sleep debt – Signs like constant fatigue or need for naps may signal you need more sleep.
  • Allow time to adjust – It may take a few weeks for a new sleep schedule to feel right.
  • Stick to a routine – Keep a consistent bedtime to stabilize your circadian rhythm.
  • Prioritize quality – Focus on improving sleep quality through good sleep hygiene habits.

Give 7.5 and 8 hours a try, then decide which leaves you feeling restored. Be patient through adjustments and optimize conditions for sound slumber.

Studies on 7.5 Hours Versus 8 Hours of Sleep

Researchers have conducted a number of studies comparing the effects of getting 7.5 hours versus 8 hours of sleep:

Cognitive Performance

A 2016 study had subjects sleep for 7.5 hours versus 8.5 hours for a week with a consistent sleep schedule. They tested subjects’ cognitive performance and mood after each week. Surprisingly, cognitive performance was better after just 7.5 hours. But when allowed to sleep in on weekends, the 8.5 hour group partially made up for sleep loss. The researchers concluded cognitive performance was more closely linked to the consistency of sleep routines rather than total sleep duration.

Reaction Time

A 2011 study looked at professional basketball players during periods of sleep loss. Athletes who slept just under 7.5 hours per night had slower reaction times and more missed shots than when they slept 8.5 hours or more. For athletes, the extra hour enhanced performance.

Sleepiness and Fatigue

In a 2013 study, healthy adults followed a restricted sleep schedule of just 7.5 hours time in bed for five nights. They then had two recovery nights with 10 hours time in bed. After the five nights of restricted sleep, subjects felt significantly sleepier during the day. However, after the first recovery night, daytime sleepiness was back to normal. Just one night of extended sleep reversed the effects of multiple nights of sleep loss.

Weekend Catch-Up Sleep

A 2018 study had subjects get around 7.5 hours of time in bed on weeknights, then extend their sleep opportunity to around 9 hours time in bed on weekend nights. The two nights of weekend recovery sleep improved their self-rated chronic sleep debt. So it seems getting extra sleep on days off can make up for lost sleep during the workweek.

Metabolic Effects

A 2015 study had healthy adults spend three weeks sleeping just 7.5 hours per night. After this period, they showed increased insulin resistance indicating impaired blood sugar regulation. This suggests regularly not getting enough sleep could negatively impact metabolism over time.

Overall the research indicates:

  • At least 7.5 hours is needed to avoid cognitive deficits.
  • For optimal cognitive performance, 8 hours or more may be best.
  • Just a few nights of 7.5 hours sleep leads to increased daytime sleepiness.
  • Two nights of extended “catch up” sleep can reverse the effects of short-term sleep restriction.
  • Chronic sleep loss can negatively impact health markers like blood sugar control.

While adults may get by temporarily on 7.5 hours, research supports 8 hours as ideal for cognitive performance and long-term health.

Sleep Quality Matters

Another key consideration beyond quantity is sleep quality. You can get 8 hours of sleep but still feel unrested. Signs your sleep is suboptimal include:

  • Having trouble falling or staying asleep
  • Frequent awakenings or tossing and turning
  • Unrefreshing sleep
  • Daytime fatigue
  • Problems with memory, mood, or focus

Poor sleep quality causes sleep debt and hinders daily performance even if you technically get “enough” sleep. So optimize your sleep hygiene by:

  • Keeping a consistent bedtime and wake time
  • Exercising regularly but not close to bedtime
  • Limiting caffeine, alcohol, and sugary foods before bed
  • Creating a cool, dark, quiet sleeping environment
  • Reducing stress and stimulation before bedtime
  • Turning off screens well before bed

Quality sleep in the right amount is key. Make improving your sleep a priority through both quantity and quality.

Individual Variation in Sleep Needs

While general guidelines exist, the ideal amount of sleep truly depends on the individual. Some signs you may need more than 7.5 hours:

  • You still feel sleepy during the day after 7.5 hours of sleep
  • Have trouble focusing on tasks
  • Depended on caffeine to get through the day
  • You nod off unintentionally during sedentary activities
  • You need long naps to get through the day
  • Have difficulty remembering things
  • Prone to errors or accidents from fatigue

If you experience any of these symptoms on a regular basis, try extending your sleep duration to see if it helps.

On the other hand, these are signs 7.5 hours of sleep may suit your needs:

  • You wake up feeling refreshed without an alarm
  • Rarely feel drowsy during the day
  • Can focus easily on tasks
  • Don’t need naps or caffeine to get by
  • Feel productive and energetic
  • No unintended sleeping during the day
  • Don’t struggle with symptoms of fatigue or sleep deprivation

If 7.5 hours leaves you feeling energetic and well-rested, your body may not require any extra sleep. But continue monitoring yourself long term for signs of sleep debt.

Changes With Age

Sleep needs can change over the lifespan. Young adults often thrive on less sleep. But as we age, sleep needs often increase.

Sleep Needs by Age

Age Recommended Sleep
Newborns 14-17 hours
Infants 12-15 hours
Toddlers 11-14 hours
Preschoolers 10-13 hours
School-age 9-11 hours
Teens 8-10 hours
Younger Adults 7-9 hours
Midlife Adults 7-9 hours
Older Adults 7-8 hours

Younger adults can often thrive on 7-8 hours of sleep, while teens need 9-10 hours. But sleep needs increase again as we age – older adults may need a full 8 hours to avoid fatigue.

Changes in Sleep Architecture

Sleep architecture refers to the structure and patterns of sleep cycles. As we age, we experience changes in sleep architecture:

  • Less time in deep slow wave sleep
  • More time in lighter stages
  • More nighttime awakenings
  • Easier disruptions in sleep

These age-related changes reduce sleep quality and mean older adults need more time asleep. So while 8 hours was perfect in your 20s, you may need 8.5 hours or more after age 60.

Finding the Sweet Spot for You

The question of 7.5 hours versus 8 hours comes down to your individual sleep needs. Try keeping a sleep diary to track data like:

  • Time you go to bed
  • Total hours slept
  • Number and length of night wakings
  • Time you wake up
  • Mood, energy, and focus ratings in the morning and evening

Look at days when you got 7.5 hours versus 8 hours. How did they compare for restedness, energy, mood, mental sharpness, productivity, exercise recovery, and health behaviors? This can help pinpoint your optimal zone.

Stick to a regular sleep-wake schedule that aligns with your body’s natural circadian rhythm by going to bed and rising at consistent times. Allow for at least 15 minutes to wind down before bedtime. Limit caffeine after noon, avoid alcohol before bed, use blackout curtains to darken your sleep environment, and reduce noise and disruptions.

Practice good sleep hygiene to ensure your sleep is continuous and uninterrupted. Take daytime naps wisely – limit to 20-30 minutes to avoid interfering with nighttime sleep.

Consistency and quality are key – your weekly average sleep duration and restfulness matter more than a single night. Give yourself several weeks to adjust to a new target sleep duration before assessing its effectiveness.

Track both quantitative measures like sleep duration along with subjective feelings of restoration and daily performance. Finding your optimal amount takes some trial and error – the right number of hours leaves you feeling refreshed and functioning at your best.

The Bottom Line

So should you sleep for 7.5 hours or 8 hours? The best approach:

  • Adults should aim for 7-9 hours nightly.
  • Try 7.5 and 8 hour schedules, assessing energy, mood, focus, productivity etc.
  • Those under 18 need 8-10 hours, and older adults need 7-8 hours.
  • Consistency and quality are just as important as quantity.
  • Listen to your body and fine-tune your sleep duration.
  • Reevaluate your needs over time as sleep changes.

While most research supports 8 hours for optimal health, some adults feel their best at 7.5. Try out different sleep durations and choose the schedule that makes you feel restored and energized. Optimizing your quantity, consistency, and quality of sleep allows you to reap the most benefits from your slumber.

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