• You can calibrate your Apple Watch to improve its accuracy in measuring your walking and running strides during a workout.
  • To calibrate your watch, just perform a walking or running workout for at least 20 minutes outdoors, where you have an unobstructed view of the sky.
  • If you have the Apple Watch Series 1 or earlier you’ll need to have your paired iPhone with you while you calibrate, as those watches lack GPS capability.
  • For the most accurate data, you should also make sure your personal data in the Watch app is up to date.
  • Visit Business Insider’s homepage for more stories.

Your Apple Watch is designed to be a very accurate health and fitness device, able to keep track of your walking, running, and workout sessions.

The watch combines estimates of average walking and running strides with your actual GPS data when you work out outdoors to track your exercise and movement activity.

You can also calibrate your Apple Watch to help it track you more accurately, which is especially important when you exercise indoors, where GPS data may be unavailable.

Check out the products mentioned in this article:

Apple Watch Series 5 (From $429 at Best Buy)

How to make sure your Apple Watch is prepared for calibration

1. Start the Settings app on your phone.

2. Tap "Privacy."

3. Tap "Location Services."

4. If it's not already on, turn on "Location Services" by swiping the button to the right.

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Foto: Make sure that Location Services is turned on.sourceDave Johnson/Business Insider

5. At the very bottom of the page, tap "System Services."

6. If it's not already on, turn on "Motion Calibration & Distance" by swiping the button to the right.

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How to calibrate your Apple Watch

To calibrate your watch, you need to perform at least 20 minutes of walking or running outdoors, so that the the watch can measure the distance you travel (using GPS) to determine your stride.

1. Wearing your Apple Watch, go outdoors to where there is a clear view of the sky so that the watch will be able to see GPS satellites.

2. Start the Workout app on your watch. It looks like a runner on a green background.

3. Tap "Outdoor Walk" or "Outdoor Run."

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Foto: You can either walk or run to calibrate your Apple Watch.sourceDave Johnson/Business Insider

4. Depending which exercise you chose, walk or run for a minimum of 20 minutes.

5. At the end of the workout, swipe right in the Workout app and tap "End."

6. This should calibrate your watch. Anytime you perform a similar workout, your watch will continue to fine-tune its understanding of your stride.

If you have an original Apple Watch Series 1 or older, you need to bring your iPhone on the calibration walk or run and make sure the phone can see the sky, since the first-generation watch doesn't have GPS.

In addition, your Apple Watch relies on your personal information (like age, height, and weight) for calibration information. Make sure that info is up to date.

1. Start the Apple Watch app.

2. On the My Watch tab, tap "Health."

3. Tap "Health Profile."

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Foto: Make sure your health profile in the Watch app is accurate and up to date.sourceDave Johnson/Business Insider

4. If you need to change any information on this page, tap "Edit" and make the changes, then tap "Save."

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