How Accurate Are Fitness Tracker? 3 Factors That Affect Accuracy

How Accurate Are Fitness Tracker?

Fitness Trackers are becoming more and more popular among fitness-conscious people in the current time. Furthermore, you can track your heart rate, count of steps you have taken, track your burnt calories, sleep monitoring, etc. You are getting access to all these features at just a glance of the tracker at your wrist, amazing, right? But, are the Fitness Trackers accurate in reality regarding their metrics of your activities?

Well, Fitness Trackers are fairly accurate in the heart rate calculation. But, the metric calculations of the step count and calories burnt have been found to be less accurate.

In fact, a paper from Standford University concludes that [which is a complex version of what I told you above]

In conclusion, most wrist-worn devices adequately measure Heart Rate in laboratory-based activities, but poorly estimate Energy Expenditure, suggesting caution in the use of Energy Expediture measurements as part of health improvement programs

Check out this paper “Accuracy in Wrist-Worn, Sensor-Based Measurements of Heart Rate and Energy Expenditure in a Diverse Cohort ” for in-depth detail.

In this article, I am going to discuss facts related to the accuracy factor of Fitness Trackers and which watch you should pick as per your goal and profession. So, stay tuned.

Why does Fitness Tracker need to be accurate?

If you are familiar with Fitness Trackers, you should already know how its market is very competitive. Many big brands compete to outdo each other with each release of their new Tracker models. 

Every new release of the Fitness Tracker model consists of new innovative features that make them more advanced.

 Nowadays, the Fitness band comes with high-tech features like heart rate monitoring, calorie count, step counts. These attributes have become the basic features that a fitness tracker should consist of. Because these days, users depend on them while performing and analyzing their health and fitness. 

Thereby, Fitness Trackers have become an inseparable part of our fitness life because we use its features for monitoring our health and fitness.

Let’s dive a little deeper into these two aspects. The following are the reason Fitness trackers should be more accurate:

Health Monitoring

Fitness Trackers are used not only for your fitness motive but also for the metric analysis of your health factors.

Through sleep tracking, blood oxygen level monitoring, and heart rate monitoring, you can track sleep patterns, heart rate, and likely disease. People depend on these features to alarm themselves of any possible health problems.ns

So, due to these health-related reasons, it is very important for the data related to these factors to be accurate.

Fitness Monitoring

Nowadays, fitness buffs do workouts, and fitness activities depend on the Fitness tracker’s features like calorie count and step count metrics. 

I myself suffer from overweight. People like me need to have a reliable metric source related to our fitness because the level of motivation required to continue the fitness activity depends on those reports.

Furthermore, People also tend to push themselves hard when training to achieve faster results. If you do not realize your body’s limitations, you can suffer from overtraining injuries. Especially, problems like heart attack, muscle injury, and organ collapse are the possible results of overtraining. 

To avoid such injuries and problems, heart rate monitors play a vital role. Because with its metric, you can train yourself while keeping your standard heart rate. 

Moreover, You do not want to get the wrong step count data neither inaccurate data on calories you burned. Because wrong data when exposed harms your source of motivation to continue

Therefore, due to these Fitness reasons, there is a vital need to have accurate metrics from Fitness Trackers.

Are All Fitness Trackers Accurate? (includes best tracker and specs)

As I have already said, there are varieties of fitness trackers from the different brands available in the market. 

The metric accuracy of all the tracker models differs; some are more accurate in particular features while others are not.

Accordingly, there is not a single fitness tracker that can give 100% accurate metric calculations of your data.

Furthermore, I will be talking specifically about the three core features present in fitness trackers 

  • Step count,
  • Heart rate monitor
  • Calories burned. 

Besides, I will also suggest the best fitness tracker with the most accurate metrics in particular features.

Step Count

Fitness Trackers use the accelerometer for counting your steps in your activity. The function of the accelerometer includes pickling up the motions. Moreover, by using the algorithm, it interprets it into step count data. 

As the accelerometers pick up on motions, they cannot distinguish whether the motion is from your feet or your hands. Also, this sensor only pickup or detects the normal pace of motion.

So if your movements are above their standard, then it will not count. For example, the number of step count differs from you shuffling on the floor to you jogging.

Talking specifically about the Fitness Tracker having comparatively the most accurate step count among other available trackers, I recommend Fitbit Charge 4

According to various user reviews, comparatively, Fitbit Charge 4 has the closest step count with the actual number of step counts. Fitbit Charge 4 tracker uses a 3-axis accelerometer sensor to count steps. The Following are the specifications of Fitbit Charge 4:

Display1.57-inch OLED monochrome touchscreen

Display resolution: 100*160 pixels

Display color depth:
Materials usedCase material: Platic Resins

Strap material: Elastomer

Bezel Material: Plastic resins
DimensionsBody dimensions: 35.8*22.7*12.5 mm

Body net weight: 27 g

Adjustable length: 140-180 mm (small band)

180-220 mm(big band)
Water resistanceYes, 5 ATM
Memory4 GB internal storage
Heart Rate MonitorYes
SpO2 SensorYes
Sleep TrackerYes
Batterynon-removable lithium-polymer

Without GPS: 7 days

With GPS: 5 hours
ConnectivityBluetooth 4.0
Supported SystemsAndroid and iOS
In the boxCharging cable

two size wrist band

user manual

warranty card
Other featuresAccelerometer

Optical heart rate monitor

Vibration motor


Heart Rate Monitoring

The Fitness Trackers that support heart rate monitoring use Photoplethysmography

This system measures the blood volume for heart rate monitoring by flashing green light on the wrist. 

But, this optical green light sensor is termed by specialists not as reliable as chest strap monitors. The green light has to penetrate the skin to read the blood activity. But, the green light gets absorbed in real-time. 

As a result, Fitness Trackers do not provide a 10/10 heart rate monitoring outputs.

Well, there are three contenders that have the most accurate heart rate monitoring metrics among all the other Fitness trackers. The contenders are Garmin Fenix 6, Garmin Vivo Smart 4, and Fitbit Charge 4. The among these three, Garmin Fenix 6 has the least difference from the actual average beats per minute, i.e., 170 max heart rate of average 155 hear rate.

The following are the Specification of Garmin Fenix 6:

Display1.3 inch (3.3 cm) MIP LCD Display

Display resolution: 260 x 260 pixels

Material UsedCase: Stainless steel

Strap material: Silicone
DimensionsBody dimensions: 1.85 x 1.85 x 0.58 inches

Body net weight: 80 g
Water resistanceYes.10ATM
MemoryRAM: –

Internal: –
Heart Rate MonitorYes
SpO2 SensorYes
Sleep TrackerYes
BatteryNon-removable [Lithium-ion polymer]

Up to 14 days
ConnectivityWiFi: Yes

Bluetooth: Yes
Supported SystemsAndroid or iOS
In the boxGarmin Fenix

Charging cable x1

User manual x1
Other FeaturesAccelerometer



Fitness Tracking

Calories Counting

The burned calorie counting in the Trackers is potentially the most inaccurate in comparison to heart rate and step count.

The normal Fitness Tracker providing the calorie count uses proprietary algorithms and proxy measures. These algorithms are considered more unreliable. 

Whereas, the big brands of Fitness Trackers allow input of your data like age, sex, height, weight, and gender. Some fitness trackers use the basal metabolic rate to calculate calories burnt. These data are further used to process and calculate how much calories you burn per day through normal actions.

According to the user’s review, Fitbit Charge 4 and Garmin Vivo Smart 4 have the least error rate of the range 20 – 25% among the other Fitness Trackers for calories counting. Garmin Vivo Smart 4 has a connected GPS. So, similarly to Fitbit Charge 4, you have the convenience to not have your phone close to your tracker. Runners, Swimmers, and Bikers, etc. will find this tracker convenient because of the GPS.

The specification table of Fitbit Charge 4 is already posted above. The following is the specification table of Garmin Vivo Smart 4:

DisplayOLED Display with touchscreen

Display resolution: 48 x 128 pixels

Material UsedCase: Stainless Aluminum, Polycarbonate, Silicone

Strap material: Silicone
DimensionsBody dimension: 0.26 x 0.7″ / 6.6 x 17.8 mm

Body net weight: 16.5 g
Water resistanceYes
Memory7 times activities, 14 days of activity tracking data
Heart Rate MonitorYes
SpO2 SensorYes
Sleep TrackerYes
BatteryNon-removable [Lithium-ion polymer]

Up to 7 days
ConnectivityWiFi: No

Bluetooth ANT+
Supported SystemsAndroid or iOS
In the boxGarmin Vivosmart 4

Charging cable x1

User manual x1
Other FeaturesFitness tracker

Pulse Ox sensor

Sleep tracker

How Can I Improve The Accuracy Of My Fitness Tracker?

Fitness Trackers do not give the most accurate measures of the metrics. But there are some ways through which you can get better readings than before from your Fitness Tracker.

The following are the ways you can improve the accuracy of your Tracker and get some fairly reliable outcomes.

Insert Correct Age, Gender, Height, Weight

If you enter your age, gender, height, and weight, your fitness tracker’s calculation of the calories will be more accurate. Calibrating is another option to increase the accuracy of calorie metric calculations.

You should make changes to these details whenever your weight or age changes.

Wear Your Fitness Tracker Firmly On Your Wrist

You should strap your Fitness Tracker as firmly as you can on your wrist concerning your comfortability. Fitness Tracker and its sensors feel a lot easier to track your movements if it stays still on your wrist. Especially for heart sensors, the band needs to stay still on the wrist for accurate heart rate monitoring.

Do Not Wear The Fitness Tracker In Your Dominant Hand

You should not wear the Fitness Tracker in your dominant hand. People automatically use their dominance more in comparison to the other hand. 

The Fitness Tracker is unable to distinguish between the hand’s movement and your step movement. 

As a result, the Tracker’s metrics output of the step count will not be accurate. So, I highly recommend not using the Fitness Tracker in your dominant hand for better accuracy of the step count.  

Fitness Calibration workout

Calories burned are usually measured by the Fitness Trackers using your distance covered in addition to your data. Moreover, the Fitness Trackers with the heart sensor provide more accurate data of calories.

Another way to get accurate metrics is by entering information related to the rate of your oxygen intake. Some Fitness Trackers and their Fitness apps have the facilities to measure your oxygen intake by analyzing your heart rate. 

Timely Firmware update

Last but not least, You should always update your Fitness Tracker and Fitness app. Many new updates containing bug fixes, improvements of old features, and new innovative updates are released. So make sure to always update your software to increase the accuracy.

Which Fitness Tracker In Overall Is the Most Accurate?

Till now, you must have known that there is no perfect Fitness Tracker that provides the most accurate metrics. But, when we think about the Fitness Tracker, that can be considered as the closest to the most accurate Tracker. Only one Fitness Tracker pops up in my mind. 

I am talking about Fitbit Charge 4 from the famous brand Fitbit. The Fitbit Charge 4 was released on April 15, 2020, by Fitbit. It is considered a budget Fitness tracker and is famous in the world of Fitness Tracker users. 

Fitbit, as a company, is one of the few brands that are ruling the Fitness tracker market. Moreover, their products give tough competition to the smartwatch market because of their product quality and features. 

There are lots of big brands in the market of Fitness Trackers like Xiaomi, Huawei, Honor, Garmin, etc. And among Fitness Tracker of those brands, the accuracy of the metric measures is becoming a big differential factor.

 Furthermore, according to user reviews, Fitbit Charge 4 is comparatively most accurate among other trackers in the current period. 

Now, Let’s elaborate on the Fitbit Charge 4’s accuracy of the 3 basic features. Furthermore, I will also be talking about 2 additional important features which nowadays are becoming essential to users.

Monitoring of the Heart Rate

The heart rate monitoring of Fitbit in comparison to other trackers is impressively accurate. It had good results while being compared to the chest strap monitor itself at the range of 190 bpm. Due to performance like this, you can obtain a satisfactory metric output of your heart rate. Fitbit measures your heart rate when you are at rest, as well as when you are working out.

In addition, Fitbit Charge 4 has a good optical heart rate sensor along with the Active Zone Minutes feature. This particular feature ensures that you are moving properly in accordance with your personalized heart rate. These two attributes contribute to its good analysis of your heart rate available 24/7.

Counting Steps

The step count on this device is also very impressive and comparatively accurate to other trackers. Fitbit Charge 4 consists of a 3-axis accelerometer that is responsible for analyzing your movements. 

This particular Fitness Tracker model also comes with an in-built GPS. As a result, you do not have to carry your phone along with you while you are active outdoors. 

The tracker continuously sends data to your fitness app via GPS. Due to this, Fitbit as a fitness tracker is very convenient if you are a Runner, Swimmer, or Cyclist.

Calorie Measurement

The calorie and fat burn metrics of Fitbit Charge 4 are also one of the most accurate among Fitness Trackers. Fitbit Charge 4, like all the Fitbit devices, combine the BMR (Basal Metabolic Rate) to calculate calories burned. The BMR is the rate of your calories burning while in a state of rest and any activity. In addition, while you are in a state of rest, heartbeat, breathing, and blood flow burn calories as well. Due to which you will find Fitbit’s calorie count satisfying and worthy to rely on. 

The following are the features other significant features found in the recent Fitness Trackers.

Blood Oxygen Level Monitoring

The Fitbit charge 4 also consists of a reliable SpO2 sensor. SpO2 sensors help to formulate the Oxygen Variation Graph in the Fitbit app. 

The advantage of data in the form of a graph is its visual patterns. The big and small variations in the graph signify warnings of higher and lower status. Accordingly, you can now have an accurate interpretation of data through this graph.

Blood oxygen level is an important aspect of trackers because they can signify or confirm an upcoming disease.

Sleep Monitoring

Sleep Tracking has become one of the essential features of the Fitness Tracking business. You will find this feature only in a few Fitness Trackers.

Whereas Fitbit’s Sleep Tracking is considered as one of the best in the business. Fitbit uses a SpO2 plus oximeter for sleep tracking, which also helps to analyze blood oxygen levels.

Using the tracker connected to the fitness app, you can make an overall estimation and score of your sleep pattern. 

With the Fitbit premium in your app, you can break down your sleep pattern into the following

  • Sleeping time
  • Deep sleep
  • Rapid Eye Movement (REM)

In addition, you can now observe the effect of late-night sleep time and alcohol in your sleep. Such detailed analysis of sleep patterns has upgraded the quality of the metric data you get from Fitbit Charge 4.

Frequently Asked Questions

Is Smart Watch More Accurate Than Fitness Trackers? 

SmartWatch, like the Apple Watch Series 6 and Samsung Galaxy Watch 3, far exceeds any fitness tracker at any time. 

The reason behind the superiority is the superior quality of the sensors and hardware used in the manufacturing of smartwatches. Sensors like Pedometer, SpO2, powerful Gps, Plus ox, barometer, gyroscope, altimeter are installed in most of the Smart Watches.

Whereas, Fitness Trackers cannot consist of all these sensors at once due to small size. Besides the Trackers that consist, some of these sensors are less powerful, thus less accurate.

Hence, SmartWatch far exceeds the Fitness Trackers in the accuracy of the metrics.

Should I Buy A SmartWatch Or Fitness Tracker?

Before deciding to buy a Smartwatch or Fitness Tracker, you should ask yourself the following questions. Afterward, you can decide to choose between the Smartwatch and the Tracker.

The following are the questions:

  • What is your budget for the purchase?
  • What purpose and activity will you use the device for?
  • What is your preferred level of compactness from the device?
  • Can your daily workouts damage the device screen?
  • Are answering calls through the device essential for you?
  • What is your preferred charging time?
  • How much should your device last from a single charge?

If you have a smaller budget, want a smaller screen, and longer battery life, then I recommend a Fitness Tracker. 

Lots of Trackers brands like Fitbit, Honor, Garmin are giving tough competition to the big shots of the smartwatch market. Fitness Trackers also consists of features identical to the Smartwatch. In addition, they are available at a much less and affordable price than Smartwatches.

In contrast, if you have a bigger budget, want more features, third-party apps, and a powerful device, then buy Smartwatch. Smartwatch is costlier than Fitness Trackers. Because they provide double the feature and quality of what a Tracker has to offer.

Final Words

Fitness Trackers have a long journey ahead of themselves before achieving the accuracy rate of 100% on their metrics calculations. 

As I have mentioned, lots of people are using Fitness Tracker in today’s time. Furthermore, the number of users only seems to be increasing with every new release. Due to this, more people are and will be depending on the metrics of Fitness Trackers for health and fitness analysis.

 Trackers help the user to complete their goals and gain faster but analyzed results. In my opinion, Trackers are truly helpful, especially for people with special and chronic health conditions. Features like oximeters, optical heart rate monitors assist those people in having better supervision of their health. So, it is even more significant for the Fitness Trackers to have a higher rate of accuracy.

Furthermore, following the release of every new model by the brands, new limits of technology are being touched through innovations. Because the accuracy rate of current Fitness Trackers is more accurate than their predecessors. Even the current accuracy rate is accurate enough for the fitness buffs regarding their fitness activities.

Hence, I believe with the current pace of technological development, soon, a 100% accuracy rate will be achieved in Trackers. 

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