What Sleep Scores Are Good for (and When They Should Be Ignored)

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Sleep tracking apps promise better rest through data. But what happens when the pursuit of a perfect score keeps you up at night? For a growing number of people, that Apple Watch, Oura Ring, or whatever device meant to improve your sleep quality may be doing just the opposite. Here’s what to know about how sleep scores really work, and what you can do to make the most of your sleep tracker.

The benefits (and accuracy) of sleep tracking

Sleep is foundational to almost every dimension of health, including “improved mood, heart health, and cognitive function," according to Dr. Rebecca Robbins, Assistant Professor in the Division of Sleep Medicine at Harvard Medical School and an Associate Sleep Scientist at Brigham and Women's Hospital. On the flip side, chronic sleep deprivation is linked to increased risk of cardiovascular disease, metabolic dysfunction, impaired immune response, and mood disorders.

For decades, however, people had a surprisingly poor grasp on how much they were actually sleeping. Self-reporting is notoriously unreliable; we tend to round up, conflate time in bed with time asleep, and forget our nighttime wake-ups entirely. “Consumer sleep tracking has begun to close that gap with significantly increased precision and accuracy in recent years, providing more insights from home," Robbins says. The Oura Ring and Whoop band dominate the scene, but watches like Fitbit or Apple Watch work too.

According to Robbins, wearables (like wrist- or ring-based devices) are equipped with multiple increasingly precise sensors: a temperature sensor, an accelerometer for movement, light sensors, and photoplethysmography (PPG) technology. (PPG uses pulses of light to detect blood movement beneath the skin, allowing the device to calculate heart rate and approximate blood oxygen saturation).

Your device tracks how long you seemed to be asleep, and makes guesses as to how much of that time was spent in light sleep, deep sleep, and REM sleep. Then, it distills it into a single composite score. It's a cool number to have, but it’s important to remember that this number is an approximation, and each company has its own grading system of sorts.

There's also the question of what "quality sleep" even means. The clinical definition centers on adequate duration (most adults need between seven and nine hours), sufficient continuity, appropriate sleep stage distribution, and, critically, how you actually feel upon waking and throughout the day. That last part is, ultimately, a subjective experience—in other words, something no wearable can measure. The person who wakes from an uninterrupted eight hours feeling groggy and unrested is not having quality sleep, regardless of what their app says. And conversely, someone who wakes feeling sharp and energized after a night their tracker graded a 65 should probably trust their body over the algorithm.

This is why it's impossible for a sleep score to be truly "accurate." Yes, all the data that going into your score (like your heart rate) might be accurate, but it's important to understand that the score itself is a made up number. Different companies have different definitions of "good" sleep, which vary from device to device. For instance, Oura and Apple both give scores ranging from 0-100, but where Oura labels a score of 70-84 as "Good," Apple has a range of 61-80 labeled as "OK." These scores aren't what you'd call clinical precision.

Still, for most people, clinical precision isn't the point. If the point is to get some behavioral feedback, then your smartwatch or sleep tracker is a great tool.

Wearables can be useful to facilitate changes in habit

Sleep tracking, at its best, functions less like a medical test that you pass or fail, and more as a way to see patterns over time. Maybe you’ll start to notice the creeping effect of a late-night glass of wine on your deep sleep percentage, or the way your resting heart rate climbs after three nights of cutting things short, or perhaps the concrete difference a consistent bedtime makes over weeks.

"People are highly motivated by their scores," Robbins says. "Wearables can foster intrinsic motivation for behavior change by providing daily feedback." In other words, your score (good or bad) can prompt you to reflect on your actions: What did I do yesterday? What can I do differently tonight?

What matters most here is that you don’t need to “optimize” every little stage of your sleep architecture to benefit from this kind of tracking. "The most powerful use of this data is when people can monitor their progress over time,” Robbins says. Rather than obsessing over your score night-to-night, you should focus on whether you're trending in the right direction.

There's also a coaching element in some of these devices, like with the Oura Advisor. In these cases, wearables might go beyond passive monitoring to actively flag inconsistencies, like alerting you to irregular bedtimes (which disrupt the body's circadian rhythm over time). I could see myself genuinely not realizing my weekend schedule is undermining my weekday sleep, and that kind of alert would help me make a necessary change. These devices are particularly powerful "for individuals who are far from a healthy sleep routine, such as those with inconsistent schedules or insufficient sleep, by providing behavioral feedback and personalized recommendations," Robbins says. 

For people who respond to positive reinforcement, the gamification built into many platforms—streak counters, badges—can also help them resist the small choices that erode sleep quality. Of course, there’s a dark side to gamification. What happens when your obsession with sleep is exactly what keeps you up at night?

Orthosomnia and sleep-tracking anxiety

Not everyone responds to data feedback with motivation. For some, daily sleep scores lead to something closer to dread.

Researchers have given this phenomenon a name: orthosomnia. The term, coined in a 2017 paper published in the Journal of Clinical Sleep Medicine, describes a preoccupation with achieving perfect sleep data that paradoxically makes sleep worse. (To be clear, this term isn't actually a formal clinical diagnosis.)

"This phenomenon typically affects individuals already prone to anxiety about judgment, where receiving daily feedback can trigger a spiral of rumination and worry that ultimately limits their ability to get good sleep the following night,” Robbins says. You slept poorly, your score reflects it, anxiety about the score increases, that anxiety disrupts the next night, which produces another poor score, and so on. The stress from receiving poor scores creates a snowball effect of more poor scores. 

This is compounded by another issue that I see again and again in the wellness space: information overload. If you’re presented with sleep stages, respiratory rate, HRV, skin temperature deviation, body battery, readiness scores, and more, it’s natural to get overwhelmed. Instead, "the most beneficial metrics for most people are often the most [simple], such as the total amount of sleep and a summary score indicating if it was a good night,” Robbins says. 

How to actually track your sleep

If you're going to use a sleep tracker, the goal is to look at broad patterns, rather than obsessing over nightly scores. Hey, sleep is variable by nature, and even healthy sleepers have bad nights. What matters is whether your weekly average is moving in the right direction. Use monthly views, not daily ones, as your primary frame of reference.

Second, identify the metrics that are actually actionable for you. If you know that your deep sleep tanks when you drink alcohol, that's useful. If you're anxiously refreshing your HRV trend without knowing what to do with it, you're probably stressing yourself out for no real reason. Robbins recommends keeping it simple: total sleep time and an overall score for whether it was a good night are often enough for most people. Another data point to start tracking: Are you lethargic throughout the day? It may be subjective, but it's a clear sign as to whether you’re getting enough quality sleep. 

Finally, know when to put the device down. "If tracking causes worry, take a break from the device, or avoid looking at the data," Robbins says. Maybe taking a week or two away from your sleep score, or simply not checking the app first thing in the morning, can break the anxiety spiral and let you approach sleep with less psychological warfare.

Some tips for getting better sleep

If you have found yourself overly reliant on sleep scores in pursuit of more restful sleep, try some other techniques instead. The fundamentals of sleep hygiene are classic for a reason.

Avoid screens before bed

We all know this one by now, but still, it’s a tough habit to break. The blue light emitted by phones and laptops suppresses melatonin production; beyond the light, the mental toll of scrolling or responding to messages keeps the nervous system in an activated state that makes it tough to fall asleep.

Replace screens with something genuinely restful

Rather than simply eliminating behaviors, adding one or two new habits might help. Robbins suggests "soothing activities such as reading a book, taking a warm shower, or practicing a mindfulness exercise."

Build in active relaxation

You don't have to wait to feel tired and hope sleep follows. Instead, try to consciously build in ways to power down. Breathing exercises, light stretching, or perhaps a simple body scan meditation can all work wonders.

Stick to your sleep schedule

Consistency around sleep and wake times is one of the strongest predictors of sleep quality, because it keeps the circadian rhythm running smoothly. 

Be honest with yourself about stimulants

This is a tough one for me, but a 3 p.m. coffee can meaningfully disrupt your 10 p.m. sleep. Alcohol, meanwhile, may speed sleep onset at first, but it hurts the second half of the night.