Like all other fitness and health trackers, the Apple Fitness app on iPhone and Apple Watch gives fairly efficient and accurate information. This is especially true when tracking health and fitness variables such as steps you’ve taken, heart rate, calories burned, and more. Speaking of calories, have you ever wondered how Apple Fitness calculates calories? In this article, I will answer the question: how does Apple Fitness calculate calories, how many you’ve burned after completing an activity or workout, and how accurate are its calculations?
How Apple Fitness App Calculates the Calories You Burn
Remember the first time you set up the Fitness app on your iPhone or Apple Watch? In case you forgot, you provided your age, gender, weight, and height. That information plays an essential part in determining your Basal Metabolic Rate (BMR) and Active Metabolic Rate (AMR). BMR is the speed at which you burn the calories you’ve ingested while in resting mode. AMR, on the other hand, is the speed at which calories are expended while you exercise. The Apple Fitness app will then use your BMR and AMR together with the personal information you provided to calculate how many calories you’ve burned.
In case you’re wondering how your iPhone and Apple Watch read all that information, credit that to the accelerometer installed on both devices. An algorithm built within the devices’ operating systems uses this information to calculate your calories burned.
How Accurate is the Apple Fitness Calories Count?
Now that you know how the Apple Fitness app on your iPhone and Apple Watch calculates the calories you burned, your next question is definitely how accurate those calculations are. Although I don’t recall Apple claiming 100% accuracy, it would be safe to assume that by basing its calculations on the scientific method, the calculations should be very accurate. Apple implemented its technology following accepted industry standards.
All that being said, the accuracy of the Apple Fitness calculations of how many calories you burn will greatly depend on the accuracy of the information you provided when setting up your Apple Watch and iPhone Fitness app. Also important is keeping that information up-to-date as things like your weight change.
The key is that the calculations Apple Fitness provides are to be taken as estimates, not an exact representation of your calorie count.
Helping the Apple Watch Improve The Accuracy of Its Estimates
Like any other measuring device or machine, your Apple Watch needs to be calibrated once in a while. Doing so will help improve its accuracy when calculating calories you burn during a workout or activity. Follow the steps below to calibrate your Apple Watch.
How to Calibrate Your Apple Watch
Before calibrating your Apple Watch, you have to make sure that it gets the information it needs. You can do this by enabling Motion Calibration and Distance settings on your iPhone.
Time needed: 1 minute
To get your Apple Watch ready for calibration, follow these steps.
- On your iPhone, go to Settings.
- Tap Privacy & Security > Location Services.
- Ensure that Location Services is turned on.
- Scroll down, then tap System Services, then toggle on Motion Calibration & Distance.
Then, you may proceed with the steps below.
- Go to a flat, open outdoor area with good GPS reception and clear skies, while wearing your device.
- For Apple Watch Series 1 owners, you need to have your iPhone with you for GPS, otherwise, you just need your Apple Watch Series 2 or later.
- Open the Workout app, then tap Outdoor Walk or Outdoor Run.
- Set a goal by tapping the three dots icon.
- Walk or run at your normal pace for around 20 minutes.
Other ways you can improve the accuracy of your Apple Watch’s calorie calculations include enabling Wrist Detection and ensuring that you wear your watch properly fitted to your wrist. Most importantly, you must ensure that you periodically update the information you provided at first setup. The same holds true for improving the accuracy of the Apple Fitness app on your iPhone.