Why is my sleep score low when I slept 8 hours?

Eight hours of sleep is great, but your tracker grades on more than just time . It's also looking at how many times you woke up, how efficient your sleep was, and signals like heart rate and HRV. Any of those going sideways can pull your score down, even on a night where you logged plenty of hours. Check your score breakdown to see what went wrong. You'll get a better idea there.

How do I increase my deep sleep score?

You cannot directly control how much deep sleep you get. Instead of trying to increase a specific score, focus on habits that support high-quality sleep . Give yourself enough time to sleep, for starters. Stick to a regular bedtime and create a bedroom environment that helps you relax. Regular exercise and avoiding alcohol/caffeine too late in the day also help. Keep in mind that wearable devices can only estimate sleep stages, so there's really no need to chase a specific deep-sleep number.

Are smartwatch sleep scores accurate?

Smartwatches are useful for tracking broad sleep patterns, but their sleep scores and sleep-stage estimates are not as precise as measurements from a clinical sleep study like Polysomnography (PSG), or even compared to an in-depth at-home sleep study . They estimate sleep using signals like movement and heart rate rather than directly measuring brain activity.

What is a normal REM sleep percentage?

For healthy adults, REM sleep makes up about 20 to 25% of total sleep . For a typical 8-hour night, that's about 90-120 minutes. Your percentage can vary from night to night, though, so one reading outside this range does not necessarily indicate a problem. If your tracker shows consistently unusual readings alongside other sleep problems, take action.

What is a normal sleep score by age?

There is no universal sleep score by age . Sleep trackers calculate scores using their own algorithms; some may consider age, others may not. So an excellent score for a 20-year-old isn't much different from one for a 60-year-old.

How do I calculate my sleep score?

You can't calculate it by yourself. Your sleep score is calculated by the device/app you're using. It combines several sleep metrics into a single number. This can include sleep duration, sleep efficiency, nighttime awakenings, sleep timing, resting heart rate, and/or estimated sleep stages.

What is a good sleep score on an Apple Watch?

Apple Watch uses a native Sleep Score from 0 to 100 . A good sleep score is around 81-95. More than 95 is considered great. Less than 81 is considered just ok. Apple calculates the score from three factors: sleep duration (50 points), bedtime consistency (30 points), and sleep interruptions (20 points). A higher score indicates that your sleep met more of Apple's targets.

Is a sleep score of 83 good?

Yes. A sleep score of 83 is usually considered good on a 0-100 scale. It means you had a solid night of sleep. Congrats! Note that your sleep score reflects many factors (sleep duration / awakenings / sleep timing / etc.). So, an 83 doesn’t mean your sleep was perfect; it indicates that your overall sleep metrics were favorable.

Is 6 hours of sleep enough?

No, 6 hours of sleep is not enough . Adults need at least 7 hours of sleep each night for good health and daytime functioning. Getting 6 hours once in a while is unlikely to be a concern, but regularly sleeping this little can affect your energy, concentration, mood, and memory to a great extent.

Can poor sleep quality lower your sleep score?

Yes. Poor sleep quality can lower your sleep score , even if you get enough hours of sleep. Frequent awakenings, restless sleep, low sleep efficiency, irregular sleep timing, etc., all affect your score. If your score falls below 70-80, check these factors along with your total sleep time to understand what may have affected it.

Sleep Score Guide

Hand holding a smartphone displaying a sleep score of 85/100 on a sleep score app.

You wake up feeling like you slept well, only to find a surprisingly low sleep score on your tracker! How did that happen? Wait, what does that number even mean? Have you been waking up with a low sleep score all these years? Is that why you're so tired every day? So many questions left unanswered...

Well, if you use a smartwatch or a sleep tracking app and want to understand what your score says about your sleep, this guide is for you. We'll cover all about how sleep scores work and what makes a good score. Most importantly, you’ll see how to use your score as a helpful benchmark rather than letting one number decide whether you had a good night’s sleep. Read on!

Key Takeaways:

A sleep score is a number (0-100) that summarizes your sleep quality based on data collected overnight by a tracker or sleep app.
Currently, there’s no standard way to calculate a sleep score. Apple, Garmin, Oura, and every other brand calculate scores differently, so a 75 on one device isn't the same as a 75 on another.
Sleep duration strongly affects your sleep score, but it’s not the only factor. Bedtime consistency, awakenings, sleep stages, heart rate, and breathing also affect it.
On 0-100 trackers, scores in the 80s are considered good. Scores in the 90s are considered excellent. A score below 80 means there's room for improvement.
One low score doesn’t necessarily mean you had a bad night. Use it to understand your sleep habits. Look at your scores over several nights to find patterns.

What Is Sleep Score?

Sleep score is a number that summarizes how well you slept based on multiple metrics, like sleep duration and interruptions. Most sleep trackers use a scale of 0 to 100, with higher scores meaning that your sleep met more of the device's targets.

Sleep score can help you track sleep patterns over time, but what it cannot do is diagnose any sleep disorders you may have. It also cannot fully determine how rested you feel on any given day. Instead, it's best viewed as a helpful snapshot of your sleep quality. Something from which you can build off of.

How Is a Sleep Score Calculated?

Infographic of factors affecting sleep score: duration, efficiency, sleep stages, interruptions, timing, physiology.

Sleep scores vary by tracker because each brand uses its own algorithm to analyze different sleep and physiological data. These include:

Sleep Duration: This measures how much time you spend asleep in total. Getting enough sleep (7-9 hours per night) contributes to a higher score, while consistently sleeping too little (less than 7 hours) brings it down. Sleeping less than 6 hours every day is really bad and can eventually lead to sleep debt to the one person you don't want to be indebted to - yourself!
Sleep Efficiency: It shows how much of your time in bed you actually spend sleeping. For example, if you spend eight hours in bed but sleep for six, your sleep efficiency is 75%. Higher efficiency indicates less time spent awake in bed.
Sleep Stages: Trackers estimate how much time you spend in light sleep, deep sleep, and REM sleep stages. These do contribute to your score, but they are not direct measurements. Wearables infer sleep stages from signals such as movement and heart rate rather than measuring brain activity like a clinical sleep study (Polysomnography).
Interruptions and Restfulness: Awakenings can affect your sleep score, especially when frequent. Brief awakenings are normal for most people, so one short wake-up does not mean you had poor sleep. But if you wake up 5-6 times and consciously remember it, your sleep becomes fragmented. Your Wake After Sleep Onset (WASO) also increases, which is the total time spent awake after initially falling asleep. The tracker flags these as poor restfulness, lowering your score.
Sleep Timing: Some trackers look at when you go to bed, when you wake up, and how consistent your schedule is from night to night. Keeping a relatively consistent sleep schedule can improve your score on devices that include timing in their calculation. It's also good sleep hygiene, so you should do it regardless of the score!
Physiological Signals: Some devices also use signals like resting heart rate, heart rate variability (HRV), respiratory rate, body temperature, and movement. Premium trackers even use photoplethysmography (PPG) sensors to read your pulse and blood flow through the skin. Changes in these measurements provide additional info about your body's activity during sleep and can influence your score.

What Is a Good Sleep Score?

On 0-100 trackers, scores in the 80s are considered good. You can use this general baseline as a reference:

Sleep Score	General Interpretation
90-100	Excellent / Outstanding
80-89	Good / Strong
70-79	Fair / Room for Improvement
Below 70	Poor / Alert to Prioritize Recovery

Your device's own scoring system is the most useful for interpreting your score. For example, Oura considers 85 or higher optimal, indicating that you’re ready to take on the day’s challenges. Meanwhile, the exact same number might mean something completely different on another tracker.

Which Devices Track Sleep Score?

You can monitor your score using everyday smartwatches (Apple, Galaxy, Pixel) or slimmer bands (Fitbit, Garmin, Whoop). If you hate bulky watches, smart rings (Oura, Galaxy Ring) track from your finger, while under-mattress pads (Withings) monitor you completely contact-free.

Pro-Tip: The most useful approach is to track your sleep over time using the same device. Since each brand calculates sleep scores differently, comparing scores across different trackers isn't ideal.

Apple Watch Sleep Score

Apple Watch calculates its sleep score from 1-100, using three factors with clearly defined weighting: sleep duration contributes up to 50 points, bedtime consistency up to 30 points, and sleep interruptions up to 20 points. Scores of 61-80 are considered OK, while scores of 81-95 are High and 96+ are Very High.

Samsung Galaxy Watch Sleep Score

Unlike Apple, Samsung does not publish an exact mathematical point breakdown for its sleep score formula. Samsung Health provides a score on a scale of 1-100, ranging through Excellent, Good, Fair, and Needs Attention. You can also use Samsung Health for additional insights like sleep consistency, snoring, blood oxygen, and skin temperature on compatible devices.

Google Pixel Watch Sleep Score

Google Pixel Watch's sleep score is influenced by factors including sleep duration, time to sound sleep, restlessness, and full awakenings. Google Health also compares your sleep data with personalized targets based on age, gender, and total time spent attempting to sleep. Scores are rated as Excellent (90-100), Good (80-89), Fair (60-79), or Poor (below 60).

Fitbit Sleep Score

Almost all Fitbit wrist devices provide a sleep score through Google Health (the original Fitbit app, officially rebranded). The same scoring applies here as it does in Google Pixel Watch: Excellent (90-100), Good (80-89), Fair (60-79), or Poor (below 60).

Garmin Sleep Score

Garmin’s smartwatches and fitness trackers monitor your sleep and send the data to the Garmin Connect app. It rates your score between 0-100, with Excellent at 90-100, Good at 80-89, Fair at 60-79, and Poor below 60. The advanced sleep tracking factors in your heart rate, heart rate variability (HRV), body movement data, and age to calculate the score.

WHOOP Sleep Score

WHOOP fitness trackers provide the Sleep Performance score (1-100%) in the WHOOP app, combining sleep sufficiency, consistency, efficiency, and stress. They also consider sleep debt and naps for a more dynamic recommendation. An optimal score requires hitting 80-90%+ on positive sleep metrics and keeping stress under 1%. A sufficient score captures mid-tier ranges like 70-90% sleep marks and 1-5% stress. A poor score means dropping below 70-80%, with sleep stress above 5%.

Oura Ring Sleep Score

The Oura Ring presents its results in the Oura app. It bases its sleep score on seven contributors: total sleep, sleep efficiency, restfulness, REM sleep, deep sleep, sleep latency, and sleep timing. A score of 85 or higher means your sleep is optimal. A score of 70-84 means your sleep is good, and you're on track for improvement. A score under 70 means your sleep is off; you may need lifestyle changes.

Samsung Galaxy Ring Sleep Score

The Samsung Galaxy Ring tracks sleep via the Samsung Health app. It uses metrics like sleep duration, sleep stages, sleep latency, and physical/mental recovery. Sleep scores from 0-59 require attention. Scores from 60-74 are considered fair. Scores from 75-84 are good. Scores from 85-100 are excellent. You can even toggle on deeper vitals like skin temperature and blood oxygen (SpO2) for personalized data.

Withings Sleep Score

Withings, along with watches, offers a different approach through devices like the Sleep Analyzer, which goes under your mattress. It uses sensors to monitor your sleep throughout the night and sends the data to the Withings app, where you can see your Sleep Quality Score along with details about your sleep patterns. The score considers factors such as sleep duration, depth, regularity, interruptions, and heart rate. With a 75+ score, you're getting high-quality sleep. With a 50-75 score, you're getting medium-quality sleep. With a 49 or below score, you're getting low-quality sleep.

Sleep Score vs. Circadian Score

Sleep score reflects aspects of your sleep quality, as you've noticed from the metrics it tracks. Circadian score, on the other hand, is a tracker-specific measure of how closely your sleep-wake schedule aligns with your circadian rhythm, the biological clock within you.

You can have a high sleep score with a weaker circadian score. For example, you might sleep for eight hours with few interruptions but go to bed at 2 a.m. and wake at 10 a.m. Your sleep quality looks good, while your sleep timing is less aligned with your circadian rhythm.

Circadian scores can also vary between apps because they use different methods to assess circadian alignment. As for which is more important, sleep score or circadian score, both are equally important for good sleep.

How to Improve Your Sleep Score

Not happy with your score? Good. That's what it's for. Let's dig into the factors behind it. Find what's dragging it down the most, and you can focus on fixing that first.

Infographic of ways to improve sleep score, including sleep duration, routine, morning light, activity, and bedtime habits.

1. Give Yourself Enough Time to Sleep

If your tracker shows that you are regularly getting less sleep than you need, start here. Most adults need at least seven hours of sleep or more each night. Moving your bedtime earlier can make a bigger difference than trying to improve a smaller sleep metric.

2. Keep Your Sleep Schedule Consistent

Try to keep your bedtime and wake-up time close to the same time each day. A consistent schedule keeps your body clock aligned, making it easier for you to maintain healthy sleep patterns.

3. Get Morning Light

Getting natural light soon after waking up regulates your sleep-wake rhythm. Spending time outside in the morning helps your body recognize when it is time to be awake and when to prepare for sleep later.

4. Avoid Screens Before Bed

Using your phone at night keeps your mind engaged when it should be settling down. Set aside some screen-free time before sleep to improve sleep quality. Read a book when it's close to bedtime. Or do something else that's relaxing.

5. Manage Stress Before You Sleep

Stress makes it harder to fall asleep and can cause you to wake up a lot during the night. Give yourself time to slow down before bed. Write down tomorrow's tasks in a journal. Practice meditation or do gentle stretching instead. Just taking a few quiet minutes before bed clears your mind up a lot.

6. Make Your Bedroom More Sleep-Friendly

Your bedroom should help you stay asleep, not make it harder. Keep the room comfortable (around 60-67°F) and free of any distractions that could wake you during the night. If you wake up often feeling too hot or in pain, you may need to upgrade your mattress and bedding.

7. Watch Your Caffeine and Alcohol Intake

Caffeine later in the day makes it harder to fall asleep. Alcohol makes you feel sleepy at first but can interfere with sleep later in the night. Pay attention to your sleep data after consuming either to see whether it affects your score. It likely does. Avoid them both hours before bedtime.

8. Stay Active During the Day

Moving your body during the day does more than burn calories. Regular physical activity has been shown to support better sleep, too. A walk, a workout, whatever you enjoy. But watch the timing. If exercising close to bedtime makes it harder to fall asleep, shift it earlier in the day.

9. Don't Obsess Over Your Sleep Score

A sleep score is an estimate based on the data your device collects. It's useful for spotting patterns, sure, but it shouldn't become something you worry about every morning. That's counter-intuitive to the whole thing! Obsessing over sleep scores can contribute to orthosomnia, a term used to describe an unhealthy preoccupation with achieving perfect sleep based on tracker data. One low score does not mean you had a bad night, just as one high score does not guarantee that you will feel great the next day.

Build Better Sleep From the Ground Up

Woman in beige silk pajamas laying down on Turmerry latex mattress with two latex pillow in a modern bedroom.

Instead of chasing a perfect sleep score, look at the habits and sleep conditions that are affecting it. Focus on one change you can make consistently, and stick with it for a while before you move on to the next one.

Your sleep environment is a good place to start. Explore Turmerry’s latex mattresses and bedding to find options best suited to your sleep setup. A cool bedroom, a comfortable mattress, a supportive topper, pillow, and bed base, layered with breathable bedding, all help create better conditions for sleep.

Frequently Asked Questions

Disclaimer: What is said in this article has been referenced from multiple sources and is intended only for educational and informational purposes. Please note that no content in this article is a substitute for professional advice from a qualified doctor or healthcare provider. Always consult an experienced doctor with any concerns you may have regarding a health condition or treatment, and never disregard any medical suggestions or delay in seeking treatment because of something you read here.