How Accurate is Fitbit’s Calories Burned Metric?

Many fitness enthusiasts rely on Fitbit to track their progress and goals. The fitness tracker, often worn on the wrist – like a wristwatch – tracks the user’s activities. It stores this information about your …

Many fitness enthusiasts rely on Fitbit to track their progress and goals. The fitness tracker, often worn on the wrist – like a wristwatch – tracks the user’s activities. It stores this information about your activity in the dedicated app on your phone. One of the most essential information the app stores is how many calories you burn doing those activities. Because many people rely on caloric information, knowing if they are accurate is essential. As a result, this article will examine how accurate is Fitbit’s calories burned metric and other tips you can use on your journey.

If you have wondered how accurate is Fitbit’s calories burned metric, the answer is that it is generally accurate. However, several factors can affect the tracker’s general accuracy. Understanding this requires understanding how Fitbit tracks calories burned. Many believe that the tracker monitors your burned calories by counting the steps you take. However, more than just that, your heart rate plays a crucial role in how the fitness tracker arrives at how many calories you have burned. Fitbit also considers your height, age, weight, and gender to come to a generally accurate estimate. You can divide these two groups of influences into clear categories.

💡 Quick Tip: The Echelon Stride-s is a portable treadmill you can use in your home to aid your calorie-burning progress.


Fitbit uses your basal metabolic rate (BMR) and heart rate to conclude how many calories you burn. Your basal metabolic rate is how many calories you burn at rest; that is, when you are not doing anything. It relies on the above factors (age, height, weight, and gender) to determine your BMR. As you would expect, it measures your heart rate via sensors that track the visible blood vessels on your wrists. Combining the two pieces of information, Fitbit arrives at a generally accurate figure regarding your calorie expenditure.

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Several factors can skew your Fitbit's results, the first of which is heart rate variability. This is because everyone’s heart rate varies, and the fitness tracker may be unable to get an accurate reading of your differing heart rate. As a result, the tracker arrives at an inaccurate heart rate and, consequently, an inaccurate number of calories you burn. Aside from heart rate variability, another suspect is wrist placement. The manufacturers of the tracker designed it to get accurate results when you wear it on your non-dominant hand. Instances like this and other incidences of wrong placement affect its accuracy. As a result, Fitbit advises that users wear their fitness trackers about two to three fingers away from their wrist bones for optimal readings. 

Another factor that can influence the tracker’s accuracy is how intense your activity is. More intensive activities and exercises may lead the tracker to overestimate how many calories you are actually burning. Likewise, less intensive activities can also affect the tracker’s reading. Many studies have demonstrated that Fitbit had the highest level of error incidences when the subject was walking. In addition, your weight can also affect Fitbit’s ability to get accurate calorie results. The tracker’s accuracy is often higher when the user’s weight falls within a certain category. As a result, if your weight is not in that category, it can affect Fitbit’s accuracy.

Another factor you may or may not expect to affect your Fitbit’s accuracy is its model. Expectedly, the costlier models would have more sophisticated BMR and heart rate trackers, resulting in better overall calorie expenditure estimates. For example, the Fitbit Charge 4 has shown high levels of accuracy among other trackers out there. Studies have shown that Charge 4 was very accurate in monitoring heart rate and steps. Expectedly, the newer model, the Fitbit Charge 5, shows even more accuracy feats than the Charge 4.

💡 Quick Tip: Not only does Fitbit track your activities and fitness goals, some models, like the Fitbit Versa, also develop unique coaching programs and offer on-screen guidance

Will the results be accurate with Fitbit on your ankle?

We have established that placement is key to your Fitbit’s accuracy. With the rising trend of wearing Fitbit on ankles, it begs the question of whether the fitness tracker would provide accurate readings on your ankle. The short answer is that you should not expect the calories burned metric to be accurate if you wear it on your ankle. This is because the manufacturers have designed it to work best when you wear it on your wrist. For example, it will only get an accurate heart rate reading by monitoring the visible veins on your wrist. 

You may also think that placing the fitness tracker on your leg will increase its accuracy in counting your steps. However, this is not so, as Fitbit tracks your steps by measuring your arm movements. Every commercially available Fitbit fitness tracker operates the same way, so you will be unable to get accurate readings from any model you use by wearing them on your ankles. Nevertheless, if your ankle is a more comfortable location to wear your Fitbit, you can get Fitbit-specific adapters to increase the tracker’s accuracy from your ankle.

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Tips for burning calories

You may have gotten your Fitbit to help you track your calorie expenditure so you can see how much you are losing. However, you need to learn how to accelerate the calorie-burning process. The short answer to burning calories is engaging in aerobic activities. The good thing is that you do not need special exercises to do this, as having an active day can help you burn a fair amount of calories.

If you need a piece of equipment to stimulate you, you can get the Jacobs Ladder – The Stairway Gtl.  Likewise, check out the Nike Romaleos 4 – Men's for your feet and the Rogue Black Ops Shorts 6.5″ 2.0 as you use the ladder. However, you should also note that it is much easier to lose calories by not eating it to begin with than by trying to burn it. So the fastest way to lose excess weight is through a healthy diet.