How Accurate Is Fitbit Sleep Tracking? - Should You Get One?

So you’ve decided to track your sleep. That’s a great idea. Many of us want our entire health tracked and recorded for us to review - that’s why we buy smart devices and health apps right?

Sleep is one of the most essential aspects of our overall health, so it’s crucial we get the data right.

But is this data accurate? It seems like a dream in theory - but if the data is wildly off, then what exactly is the benefit of buying these watches? What’s the point of the feature?

We’re going to look at this more deeply. Sit down, relax - just don’t catch some Z’s right now!

What Is Fitbit And Its Tracking Feature?

Sleep tracking device in use on arm at night

Fitbit is a well known brand now. It manufactures smart devices that are aimed at fitness and wellbeing recording. These features usually include a heartbeat sensor, oxygen level sensor and a sleep tracker - along with your bluetooth for calls and texts to come through.

The Sense version of Fitbit also has further health features like monitoring the temperature of your skin and indicating your levels of stress.

Fitbits understand and learn movement patterns, exercises like hiking, bicycle riding, running and walking. It can also record your movement and overall health by technology known as an accelerometer. This converts physical data into Fitbit’s digital data. This is basically how the device can measure your heart rate or sleep.

If you’re wearing your Fitbit in bed, you haven’t moved for an hour and Fitbit recognizes this as your normal sleep routine - it will begin tracking your sleep. It will record data such as restlessness (moving around during your sleep) and “awake time.” If you’re moving a lot in your sleep time, it will register this data as being awake.

Your information is then stored on the device(s) of your choosing such as your smartphone, tablet or computer.

You can set yourself some personal targets which Fitbit will reward you with, indicating a star. If you’re within half an hour of your sleep target, you’ll grab yourself a star! It will even remind you to go to bed, if you’ve set a target sleep time.

There are two main settings. Normal and sensitive. Normal will work… as normal. It will record movements only if they are excessive in your sleep. However, the sensitive setting will record pretty much any sort of movement.

Sounds Great! How Accurate Is It Though?

How accurate are the tracked sleep data - women in pajamas holding phone with sleep data

That’s actually more difficult to answer than you’d think. For tracking your sleeping routine it is pretty much guaranteed to be correct - that’s because you’re recording it. However, when it comes to your sleep - there’s several things to think about.

One study theorized that the Fitbit sleep tracker indicates a positive start to this type of technology, but can be overly sensitive and therefore your results aren’t going to be 100% accurate. This might be off-putting, but it is still a good indicator of your sleeping data.

As the technology grows, the devices are becoming more sophisticated. Most have agreed that the newer models are providing a more accurate portrait of their data. Newer models of Fitbit have a sleep-staging feature, which uses measurement data into its own algorithm.

These sleep stages are:

(1) Light Sleep

As the name light sleep suggests, this is where you are recorded as being just asleep. In other words, you could be woken up by someone calling you or tapping you.

(2) Deep Sleep

You’re now difficult to wake up, your breathing is slower and your body and mind are recovering. Waking up in the morning, you should be feeling fresh. This deep sleep is great for your immune system too!

(3) REM Sleep

REM (or rapid eye movement) sleep is the deepest form of sleeping. This is where you begin to dream and have a highly active brain. This type of sleep is where your mind begins to think things through. It really is true to the phrase “I’ll sleep on it.” It can help!


There are drawbacks to the Fitbit sleep tracker. Firstly, it cannot tell you if you have any form of sleeping disorder. When it comes down to it, nothing beats a specialist for that.

Many users of the device have said that it doesn’t always track data - sometimes waking up to find that no data was recorded at all! This could be due to your fitbit moving off your wrist during sleep, meaning the device was unable to identify your heart rate.

It could also be due to the user going to bed with a low battery - meaning the Fitbit dies during your sleep.

The device will also fail to record anything if your sleep is less than 180 minutes. So if you wanted your napping in your health data, you’re out of luck.

Top Points

Is the Fitbit sleep tracker accurate?

- Not 100% accurate but pretty close. The likelihood is that it will get more accurate too!

Is getting a Fitbit worth it to track my overall health?

- If you’re keen to track your health, including your sleep, then sure!

Are there any more accurate sleep trackers on the market?

- There are no 100% accurate sleep trackers (without specialists being present or recording the data.) Customers for the majority of products that record health data have reported some level of inaccuracy (whether that is sleep or heart rate etc.)

Does tracking my sleep benefit me?

- It can be useful! Fitbits sleep staging could give you an idea of how your sleep is going, even if it’s not 100% accurate. It is probably more important to note your movements in your sleep - if they’re excessive or you don’t recognize them, then maybe speak with a professional about your concerns.

In Summary

The choice of buying a Fitbit for its sleep tracker is at your feet. Tracking your sleep can be hugely beneficial, just don’t expect it to be definitely accurate. We all need to ensure we’re getting enough sleep and this device can be a good start!