1. Improve step counting and distance accuracy
  2. Improve sleep tracking accuracy
  3. Calibrate exercise detection
  4. Improve swim tracking accuracy
  5. How to improve heart rate accuracy
  6. Which wrist are you wearing your Fitbit?

How to calibrate your Fitbit for better accuracy

Tune the tracker to your wrist with these handy tricks
Fitbit Lifestyle photo of Fitbit Charge 4.
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We've all looked down at our Fitbit and wondered how it really knows what our heart rate is, or whether it's really able to log every step accurately.

Through our testing, we've found Fitbit to be among the most accurate in sleep tracking, heart monitoring and step counting, with its in-house algorithms improving all the time.

Still, did you know it's possible to actually improve the accuracy of your Fitbit by tweaking some settings?

By calibrating your Fitbit Versa, Charge, or even basic trackers like the Inspire 3, you're giving it a helping hand in logging your activity from the wrist - whether that's floors climbed, hours slept, or calories burned.

Here are five ways to change the settings to ensure you get the very best results.

Improve step counting and distance accuracy

FitbitRunning accuracy

If you're finding your Fitbit is off the mark with tracking distance or steps, adjusting your stride length will help. Even if it's generally accurate, setting a manual stride length will ensure you're not overestimating or underestimating your daily activity and workouts.

Find out by walking (or running) over a short distance and then dividing that total distance by the number of steps taken. You can enter different stride lengths for running and walking, so make sure you do it for maximum accuracy.

1. In the Fitbit app, tap the 'Account' icon which should be the icon with your profile photo if you've used one. Then scroll down to 'Activity and Wellness' and tap.

2. Next, select 'Exercise' and you should see an option for 'Stride Length'. If you haven't tweaked this before, it's likely to set to automatically track your steps, adjusting whenever you've run with GPS enabled depending on your device's support.

3. If you toggle it off, you'll be able to set this manually.

Improve sleep tracking accuracy

FitbitSleep accuracy

You can calibrate your Fitbit for sleep, even if you don't have the advanced Sleep Stages and Sleep Insights features. Adjusting sensitivity differs depending on whether you're paired with an iPhone or Android phone. For iPhone users:

1. In the Fitbit app, go to Account > Activity & Wellness > Sleep.

2. By default, this will be set to 'Normal', but you can tweak it to 'Sensitive' if you find that the tracker isn't registering your sleep, or is registering odd results.

3. For Android users, you'll need to log into the web dashboard, go to the settings tab, and scroll down to the page to find the ability to toggle sleep sensitivity between normal and sensitive options.

Calibrate exercise detection

Through Fitbit SmartTrack, workouts are automatically detected, including walking, running, cycling, and even swimming.

By going into 'Account', 'Activity & Wellness, and then into 'Exercise', you can tweak how long Fitbit will wait to kick in tracking when it automatically detects an exercise is happening.

The shortest amount of time you can set this for is 10 minutes, but, don't worry, any exercise you do in those first few minutes will still be accounted for.

However, if you find auto-tracking isn't working quite right, even once you've adjusted the time, you can turn it off for each exercise individually.

Improve swim tracking accuracy

FitbitVersa accuracy

If you want to track a swim session, make sure you've calibrated the tracker to the length of the pool. You can do this by going into your Account > Activity & Wellness and going to Exercise. Then tap through to the swimming option to adjust the pool length.

On the Sense and Versa series smartwatches, you can do this before each swim on the watch itself by tapping the cog icon in the top left and adjusting the distance.

Make sure you do this to ensure the best accuracy in the pool.

How to improve heart rate accuracy

FitbitHeart rate accuracy

Most of Fitbit's devices include an optical-based heart rate monitor. Just the Sense currently offers an additional ECG sensor to offer medical-grade readings of your heart. For that optical sensor, there are some ways to improve the accuracy of readings.

The first thing to do is to make sure you're wearing your Fitbit on top of your wrist and the back of the device is in contact with your skin.

If you're exercising with it on, make sure to get a slightly tighter fit to reduce the chances of movement which can impact on the sensor taking readings. Crucially, you don't want it to be constricting or tight that it feels uncomfortable to work out with.

When you're not using the heart rate sensor during exercise, make sure you wear your device finger widths above your wrist bone.

Which wrist are you wearing your Fitbit?

A small point, but still important: make sure you tell the Fitbit app which wrist you're wearing your Fitbit on.

You can do this by going into Account in the top left of the Today page, then tapping on your synced Fitbit device. From there, you can scroll down the page where you'll see Wrist Placement. You can tap to switch between dominant and nondominant options.

What difference does that make? Well, wearing the device on your dominant hand decreases sensitivity to step counting and over counting when you're not moving. Wearing your Fitbit on the non-dominant wrist increases the sensitivity of step counting and reduces underreporting of steps.

How we test

Michael Sawh


Michael Sawh has been covering the wearable tech industry since the very first Fitbit landed back in 2011. Previously the resident wearable tech expert at Trusted Reviews, he also marshaled the features section of T3.com.

He also regularly contributed to T3 magazine when they needed someone to talk about fitness trackers, running watches, headphones, tablets, and phones.

Michael writes for GQ, Wired, Coach Mag, Metro, MSN, BBC Focus, Stuff, TechRadar and has made several appearances on the BBC Travel Show to talk all things tech. 

Michael is a lover of all things sports and fitness-tech related, clocking up over 15 marathons and has put in serious hours in the pool all in the name of testing every fitness wearable going. Expect to see him with a minimum of two wearables at any given time.

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