Sleep score: what it measures and what a good score is

A sleep score is a single number, usually from 0 to 100, that summarizes last night's sleep from how long you slept, when you went to bed, how often you woke up and, on some devices, your estimated sleep stages. On most wearables, 80 or more is a good score and 90 or more is excellent. The scale is brand-specific, so a score only means something next to your own earlier scores.

This guide explains what goes into each major sleep score, what counts as a good number on each device, what the research says about the parts that matter, and how to raise a low score.

What is a sleep score?

A sleep score is a composite rating that a sleep tracker computes each morning from estimates of sleep duration, sleep timing, sleep continuity and sometimes sleep stages. It turns several measurements into one number so you can see at a glance whether last night was better or worse than usual. It is an estimate, not a clinical measurement.

Every brand builds its score differently. Apple Watch, Fitbit, Oura and Garmin all use a 0 to 100 scale, but they choose different inputs and weight them differently. That is why the same night can score 78 on one device and 86 on another.

Three ideas sit underneath almost every score:

• Quantity: did you sleep long enough? Adults need 7 or more hours per night, according to the American Academy of Sleep Medicine and Sleep Research Society consensus (Watson et al., 2015).
• Timing and regularity: did you go to sleep at a similar time to other nights?
• Continuity and depth: did you sleep through, and how much time did the device estimate in deep and REM sleep?

For the stage terms, see our guides to what core sleep is on Apple Watch and how much deep sleep you need.

What is a good sleep score?

A good sleep score is 80 or higher on Fitbit and Garmin, 85 or higher on Oura, and 81 or higher (High) on Apple Watch. Scores of 90 and above are rare on every platform. Fitbit says most users average 72 to 83, and Garmin reported a user average of 72 for February 2024 to January 2025.

Here is how each brand labels its scale, from each company's own documentation as of October 2026:

Device	Top band	Good band	Middle band	Low band
Apple Watch	Very High: 96 or more	High: 81 to 95	OK: 61 to 80	Low: 41 to 60; Very Low: 0 to 40
Fitbit	Excellent: 90 to 100	Good: 80 to 89	Fair: 60 to 79	Poor: below 60
Oura	Optimal: 85 to 100	Good: 70 to 84	Fair: 60 to 69	Pay attention: 0 to 59
Garmin	Excellent: 90 to 100	Good: 80 to 89	Fair: 60 to 79	Poor: 0 to 60

Sources: Apple Support, Fitbit Help, Oura Member Care, Garmin blog (2025).

Two practical points follow from the table. First, a 75 is "Fair" on Fitbit and Garmin, "Good" on Oura and "OK" on Apple. Second, a perfect 100 is designed to be rare. Oura says so directly, and Garmin reported that only 7% of its users averaged an Excellent score.

What does a typical person score?

Fitbit states that most users see an average sleep score between 72 and 83. Garmin's 2025 analysis reported an average of 72, with 31% of users averaging Good, 43% Fair and 19% Poor. Garmin also found that users who slept 8 to 8.5 hours averaged 78, while users who slept about 4 hours averaged 35. In that data, duration showed the clearest link with the score.

What goes into a sleep score?

Most sleep scores combine total sleep time, a timing or consistency measure, a wake-up or restlessness measure and, on some devices, stage estimates. Apple weights duration at 50 of 100 points. Oura uses seven contributors. Fitbit uses duration, sound sleep and awakenings. Garmin uses heart rate, heart rate variability and movement to estimate stages and awake time.

Device	Inputs named by the manufacturer	Uses sleep stages?
Apple Watch	Duration (50 points), bedtime consistency over the last 13 nights (30 points), interruptions (20 points)	Not as a named component
Fitbit	Sleep duration, time to sound sleep, sound sleep, restlessness, full awakenings, interruptions	Yes, the device must track stages
Oura	Total sleep, efficiency, restfulness, REM sleep, deep sleep, latency, timing	Yes
Garmin	Heart rate, HRV and movement to estimate sleep timing, awake time and light, deep and REM sleep	Yes

Sources: Apple Support, Fitbit Help, Oura Member Care and blog, Garmin blog.

Apple's design is notable: it does not score stages at all. The Apple Watch sleep score guide breaks down how each of its three parts earns points.

What is sleep efficiency?

Sleep efficiency is the percentage of your time in bed that you actually spend asleep. If you are in bed for 8 hours and asleep for 7, your efficiency is 87.5%. Oura uses efficiency as one of its seven contributors. The National Sleep Foundation's checklist treats "mostly asleep while in bed (7 out of 8 hours)" as one sign of good sleep quality.

The same National Sleep Foundation checklist lists three more markers of good sleep quality:

Marker	Adults	Older adults
Time to fall asleep	30 minutes or less	30 minutes or less
Awakenings per night	1 or fewer	2 or fewer
Time awake after falling asleep	20 minutes or less	30 minutes or less
Time asleep while in bed	About 7 of 8 hours	About 7 of 8 hours

Source: National Sleep Foundation, Sleep Quality At-A-Glance, 2024.

Answering yes to most of these suggests good sleep quality, according to the NSF. Note that this is a checklist for self-assessment, not a diagnostic test.

Which parts of a sleep score matter most for health?

Duration and regularity have the strongest research behind them. The AASM and SRS recommend 7 or more hours for adults. A UK Biobank study of 60,977 adults found that more regular sleep timing was associated with a 20% to 48% lower risk of death from any cause. Expert panels found less agreement on sleep stages as quality markers.

• Duration. The AASM and Sleep Research Society consensus states that adults should sleep 7 or more hours per night on a regular basis to promote optimal health (Watson et al., 2015). That is why every major score gives duration the most weight.

• Regularity. Windred et al. (2024) calculated a Sleep Regularity Index from accelerometer data in 60,977 UK Biobank participants. Compared with the least regular group, the more regular groups had a 20% to 48% lower risk of all-cause mortality over about 6 years of follow-up, after adjusting for age, sex and lifestyle factors. Sleep regularity was a stronger predictor of mortality than sleep duration in that study. This is an association from an observational study, not proof that changing your bedtime changes your risk, but it is a good reason that Apple gives bedtime consistency 30 of 100 points.

• Continuity. Time to fall asleep, the number of awakenings and time awake after sleep onset all made the National Sleep Foundation's list of good-quality indicators.

• Stages. The same NSF expert panel reported less or no consensus on sleep architecture (the share of each stage) as a marker of sleep quality. Stage estimates from a wrist or finger device are also the least accurate part of a sleep report. Treat stage numbers as a rough guide. Our articles on how much REM sleep you should get and how to get more deep sleep cover what the research says about each stage.

How accurate are sleep scores?

Sleep scores are only as accurate as the sleep and wake estimates beneath them. In a 2021 laboratory study of seven consumer devices against polysomnography, all devices detected sleep well (sensitivity of 0.93 or higher) but detected wake poorly (specificity 0.18 to 0.54). Stage estimates were inconsistent across devices.

Polysomnography (PSG) is the clinical gold standard. It records brain waves, eye movements, muscle tone, breathing and heart rhythm in a sleep lab. A wearable estimates the same night from movement and heart rate.

The Chinoy et al. (2021) study tested 34 healthy young adults over three nights. Its key findings:

• Devices were good at detecting when you are asleep.
• Devices were weaker at detecting short periods awake, so they can overestimate total sleep.
• Sleep stage comparisons with PSG were mixed.
• Devices performed worse on nights with disrupted sleep.

What this means for you: use your score to see direction and trend over a week or more. Do not read a 3-point change as meaningful. Duration and timing, which drive most of the score, are the most reliable parts.

Why is my sleep score low?

A low sleep score most often comes from a short night, a bedtime far from your usual one, or several wake-ups. Alcohol, late caffeine, a warm bedroom, late exercise, stress and illness can all be associated with lighter, more broken sleep. Check which component dropped before changing anything.

Likely cause	Component it usually lowers	What to check
Less than 7 hours asleep	Duration	Time in bed vs your target
Late or irregular bedtime	Consistency or timing	Bedtime vs your average of the last 1 to 2 weeks
Waking several times	Interruptions, restlessness, efficiency	Noise, light, temperature, bathroom trips
Alcohol in the evening	Interruptions, REM, efficiency	Drinks and timing
Caffeine after midday	Time to fall asleep, duration	Last coffee, tea or energy drink time
Feeling unwell	Several components, plus higher resting heart rate	Other symptoms

If your score is low because you wake up often, snore loudly, stop breathing during sleep (as noticed by a partner), or feel very sleepy during the day despite enough time in bed, talk to a doctor. These can be signs of a sleep disorder that a wearable can not diagnose.

For a closer look at timing, see when to stop caffeine before bed. For the effect of a short week, see sleep debt and how to pay it back.

How can I improve my sleep score?

The fastest way to raise most sleep scores is to give yourself at least 7 hours of sleep opportunity and to go to bed at about the same time every night. Those two steps lift the duration and consistency components, which make up most of the score on Apple Watch and carry heavy weight on other devices.

A practical order of operations:

1. Set a fixed wake time you can keep on most days, including weekends.
2. Count back 7.5 to 8 hours to set a bedtime. Adults need 7 or more hours asleep, and some time in bed is spent awake.
3. Keep bedtime within about 30 minutes of your usual time most nights.
4. Move caffeine earlier. Caffeine has an average half-life of about 5 hours in healthy adults, so an afternoon coffee is still partly active at bedtime.
5. Keep alcohol away from bedtime if your interruptions or REM numbers are low.
6. Keep the bedroom cool and dark.
7. Change one thing at a time and watch the trend for a week.

Most devices also let you see which component moved. Fix the weakest component first.

Does a sleep score match how rested I feel?

Not always. A score reflects measured duration, timing and wake-ups, while how rested you feel also depends on your individual sleep need, stress, illness and time of waking. Studies show wearables miss some time awake, so a score can look better than the night felt. Use both the score and how you feel.

If the score is consistently good and you still feel unrefreshed, the score is not the full picture. Persistent daytime sleepiness despite 7 or more hours in bed is a reason to see a doctor.

How is a sleep score different from a readiness or recovery score?

A sleep score rates last night only. A readiness or recovery score answers a different question: how prepared your body is for strain today. It usually combines recent sleep with overnight heart rate, heart rate variability, temperature and recent activity, compared with your own baseline. Sleep is one input, not the whole score.

Because the two scores answer different questions, they can disagree. Sleep tells you about recovery time. Overnight heart data tells you how your body handled the day before, including training, alcohol, heat or the start of an illness.

So a good sleep score with a low readiness score is possible, for example after a hard workout or during an illness. Our recovery score guide explains how those scores use HRV and resting heart rate.

Do naps count toward a sleep score?

It depends on the device. Fitbit, for example, bases its sleep score on total estimated sleep during your main sleep window, so a separate afternoon nap does not change last night's score. Some devices count naps in daily sleep totals that feed other scores. If you nap often, check how your device treats naps before comparing days.

A practical rule: judge your nightly score on the main sleep period, and judge your total rest across the full 24 hours. A long afternoon nap can make it harder to fall asleep at your usual bedtime, which may cost consistency points the next night.

How many nights do you need before a sleep score means something?

One night tells you little. A sleep score is most useful as a weekly or monthly average, because single nights vary with noise, stress, travel and measurement error. Apple's bedtime consistency part alone looks back over 13 nights, so a fair first read of any score needs about two weeks of data.

A simple way to read your scores:

Time frame	What to look at	What to ignore
One night	Which component dropped, and an obvious cause	Small changes of a few points
One week	Average score and average time asleep	One unusually good or bad night
One month	Trend direction after a habit change	Day-to-day stage percentages

Lab testing found that consumer devices performed worse on nights with disrupted sleep, which is one more reason to judge averages rather than single bad nights.

How Svanu calculates its sleep score

Svanu computes its own sleep score from 0 to 100 on your iPhone, using sleep data from Apple Health. It works with Apple Watch and with other devices that write sleep to Apple Health. The score shows its inputs and what moved it.

Component	Weight	How it is scored
Duration	50%	Sleep vs your sleep need
Stage quality	30%	Deep and REM share of the night, from the stages your device estimates
Bedtime consistency	20%	Standard deviation of recent bedtimes: 30 minutes or less scores full, 120 minutes or more scores zero

The Sleep screen also shows your stages, your running sleep debt and a suggested bedtime for tonight. That bedtime works back from your own median wake time and your sleep need, and pays debt down over about a week, at most one extra hour per night. All scores are computed on the phone, with no account and no health database on a server. You can see how the app works or read how to track sleep on Apple Watch first.

Related reading

• Apple Watch sleep score: how it works
• What is core sleep on Apple Watch?
• How much deep sleep do you need?
• How much REM sleep should you get?
• Sleep debt: how to calculate it and pay it back
• Sleep cycle alarm: does waking in light sleep work?
• Stress score: how wearables measure stress from HRV