How Accurate Is Fitbit Calorie Burn? – TRUTH REVEALED!

How Accurate is Fitbit Calorie Burn

When it comes to tracking our fitness goals, Fitbit has been a trusty companion for many of us. 

They’re one of the most popular types of wearable technology used by millions of people across the globe.

From step counts to heart rate monitoring, Fitbit devices offer a bird’s eye view into our overall fitness progress.

One of the key metrics that many people rely on is calorie burn — the number of calories we purportedly burn throughout the day while exercising and engaging in various activities.

But have you ever wondered how accurate is Fitbit calorie burn calculation? 

After all, precise data matters when it comes to achieving our health and fitness goals. 

Whether you’re trying to shed a few pounds, maintain your weight, or boost athletic performance, understanding the accuracy of Fitbit’s calorie burn estimates is crucial.

In this post, I’ve explained if Fitbit calorie burn calculations are accurate, the factors that affect it, and some tips to maximize your device’s accuracy.

How Accurate is Fitbit Calorie Burn?

Fitbit has undergone rigorous testing to validate its calorie burn estimations. However, real-life experiences of Fitbit users have shown mixed results. 

In fact, a recently conducted meta-analysis of 29 different studies on Fitbit devices also found that the calorie burn calculation is not entirely accurate. 

However, you can still rely on Fitbit’s calorie burn results as a reference point for tracking progress and trends in your overall fitness level.

How Do Fitbit Devices Calculate Calorie Burn?

There are 4 components based on which Fitbit devices calculate how many calories you have burned. 

Let’s discuss each component in detail and understand how they come together to calculate your burned calories.

Step Count & Distance Traveled

The first component that Fitbit devices take into consideration is your step count and the distance you’ve covered. 

As you may already know, Fitbit devices come equipped with an accelerometer that detects your movements, translating them into steps.

Based on the number of steps you walked, Fitbit devices can estimate the distance you’ve covered. And these two pieces of information eventually determine the number of calories you’ve burned throughout your day.

Basal Metabolic Rate (BMR)

Basal Metabolic Rate (BMR) is another key component of Fitbit’s calorie burn calculation. 

For the uninitiated, your BMR represents the number of calories your body needs to maintain basic functions like breathing, circulating blood, and regulating body temperature while at rest. 

It’s like the fuel your body needs to survive if you were lying in bed all day.

Fitbit devices take your BMR into account before calculating the additional calories burned through physical activities. 

By combining your BMR with the data collected from your steps and distance, Fitbit has a solid reliable source to estimate your total calorie burn.

MET Values

Fitbit uses MET (Metabolic Equivalent of Task) values to factor in the intensity of different activities. 

MET is a unit that represents the energy expenditure of an activity relative to your resting metabolic rate. 

For instance, sitting quietly has a MET value of 1, while running might have a MET value of 8 or more, depending on the speed.

When you start an activity and your Fitbit recognizes the motion patterns associated with it, it looks up the MET value for that specific activity and uses it in the calorie calculation formula. 

This additional data helps provide a more accurate picture of your energy expenditure during various exercises and daily tasks.

Heart Rate Monitoring

Last but not least, Your heart rate is a reliable indicator of how hard your body is working during physical activities. 

Fitbit devices factor in your heart rate data to further improve their accuracy of calorie burn calculations.

In simple words, when you engage in exercises that get your heart pumping, the device uses this information to better understand the intensity of the activity. 

This means activities like jogging or cycling will be more accurately represented in terms of calories burned.

Factors That Can Affect the Accuracy of Fitbit’s Calorie Burn

Now that you’ve finally how Fitbit devices calculate calorie burn, let’s also discuss some of the key factors that can affect its accuracy.

1 – Weight

 Your weight plays a significant role in determining how many calories you burn during various activities. 

Fitbit uses your weight to estimate energy expenditure based on known metabolic equations. So, if your weight isn’t up to date in your Fitbit profile, the calorie calculations may not be as accurate. 

Therefore, I strongly recommend updating your weight information daily, or at least weekly basis, to get accurate results.

2 – Wrist Placement

Believe it or not but how you wear your Fitbit can also impact the accuracy of calorie burn readings. 

If you want to get accurate calorie burn calculations, ensure that your Fitbit is snugly fastened around your wrist. 

A loose or improperly positioned device might not be able to capture your movements as effectively, which can easily result in potential inaccuracies.

3 – Heart Rate Patterns

Fitbit devices with heart rate monitors are fantastic for tracking your pulse during workouts and daily activities. 

However, irregular heart rate patterns or movements that interfere with the heart rate sensor’s contact can result in inaccurate calorie burn calculations. 

So, make sure to wear your Fitbit slightly higher on your wrist and secure it properly to maintain a consistent heart rate reading.

4 – Activity Type

Different activities require varying amounts of energy, and Fitbit uses different algorithms to estimate calorie burn for each activity type. 

While it’s pretty good at detecting common exercises like walking, running, or cycling, it might struggle with accurately tracking lesser-known or complex movements. 

If you’re engaging in an unusual activity, consider using activity modes to improve the accuracy of your calorie burn calculations.

5 – Overall Activity Level

Your Fitbit calculates calorie burn based on your daily activity level, not just the time you spend exercising. 

It considers your basal metabolic rate (BMR) as well, which is the energy your body needs to perform basic functions at rest. 

So, if you spend most of your day sitting, the calorie burn estimation might be lower than expected. On the flip side, if you’re incredibly active, the readings could be higher than your actual calorie expenditure.

Tips for Maximizing Fitbit’s Calorie Burn Results

If you want to generate the most accurate calorie burn results, there are certain things you need to take care of once in a while.

Update your Personal Data Regularly

Making sure your personal data is up-to-date & accurate is crucial for getting precise calorie burn results. 

So first things first, check that your height, weight, age, and gender are correctly entered in your Fitbit app. 

When these details are up to date, your Fitbit can better estimate your basal metabolic rate (BMR) – the number of calories your body needs to function at rest.

Additionally, you should also adjust your activity level in the app to match your current lifestyle. If you’ve recently started a new workout routine or changed jobs to one that keeps you more active, be sure to reflect these changes in your profile. 

This will help to improve your calorie burn result accuracy.

Wear your Device on your Non-Dominant Wrist

You might be surprised to learn that the wrist you choose to wear your Fitbit on can make a difference. 

While it may seem like a small detail, wearing your device on your non-dominant wrist can lead to more accurate calorie burn readings. 

Here’s why – Your non-dominant wrist is generally less active throughout the day compared to your dominant one. As a result, it is less likely to register false steps or movements that could throw off your calorie calculations.

So, if you’re right-handed, try wearing your Fitbit on your left wrist, and if you’re left-handed, wear it on your right wrist. 

It might take a little getting used to, but it is definitely worth it to see those calorie-burn numbers getting more precise.

Utilize Activity Modes 

Did you know that your Fitbit comes with a bunch of activity modes designed to track specific exercises? 

Whether you’re going for a run, hitting the gym, cycling, or even practicing yoga, there’s an activity mode for almost every type of workout you can think of. 

These modes help your Fitbit zero in on the unique movements and intensities associated with each activity, giving you more accurate calorie burn results.

To use an activity mode, simply open the Fitbit app, swipe to the Exercise screen, and select the mode that matches your workout.


So, how accurate is Fitbit calorie burn? As you just learned, Fitbit calorie burn results are not 100% accurate but they still provide a reasonably accurate estimation of burned calories. 

Remember, the most crucial aspect of your fitness journey is consistency and staying active. 

So, whether you’re burning precisely 300 calories or 315 during that morning jog, the key is to keep moving, stay motivated, and enjoy the journey toward a healthier you!

Jaimin Kapadia

Jaimin is an avid gadget lover & wearable tech enthusiast. Every day, he reads about the latest wearable devices launched around the globe and writes about his experience and review on this blog.

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