Trusted Reviews is supported by its audience. If you purchase through links on our site, we may earn a commission. Learn more.

How to measure your blood oxygen on an Apple Watch

The Apple Watch has become an exceptional health tool, packing numerous features to help keep an eye on everything from your heart rate to sleep.

One of the newer health features added to recent Apple Watches is the ability to measure your Blood Oxygen level and in this guide we’ll show you how to do it.

Before we start it’s worth noting this feature is only available on the Apple Watch Series 6 and Apple Watch Series 7, so if you have an older Apple Watch or an Apple Watch SE then you’re out of luck.

What you’ll need: 

  • An Apple Watch Series 6 or Series 7 (we used the Series 7 for this guide)

The Short Version 

  • Open the app list on your Apple Watch
  • Find and open the Blood Oxygen app
  • Start the test
  • Note the result
  1. Step

    Open up the list of apps on your Apple Watch

    With your Apple Watch on your wrist open up the list of installed apps by pressing the Digital Crown on the side of the watch. Open up the list of apps on your Apple Watch

  2. Step

    Scroll down to the Blood Oxygen app

    Swipe down the list of apps until you find the one called Blood Oxygen. Tap the app to open it up.Scroll down to the Blood Oxygen app

  3. Step

    Hit Start and keep still

    Once the app is open, hit the big Start button while ensuring your wrist is still and the Apple Watch is as close to your skin as possible.Hit Start and keep still

  4. Step

    Wait 15 seconds

    The app takes 15 seconds to gather a reading and you’ll see a countdown on the display of the watch. Remember to keep still for the duration.Wait 15 seconds

  5. Step

    Take note of your results

    Once the countdown has finished your result will appear as a percentage on the screen. You can now either leave the app or conduct the test again. Take note of your results


How can you avoid getting the Measurement Unsuccessful message?

If you have followed the above instructions and received a Measurement Unsuccessful message then make sure your Apple Watch is as close to the skin as possible and you’re staying as still as possible throughout the whole 15 seconds.

What does the result mean?

The oxygenation of your blood is vitally important because it allows your cells to create energy through respiration, with it can then power all of your essential bodily functions. The NHS advises that you should ask for medical help if your SpO2 number stays at 92% or less.

Why trust our journalism?

Founded in 2003, Trusted Reviews exists to give our readers thorough, unbiased and independent advice on what to buy.

Today, we have millions of users a month from around the world, and assess more than 1,000 products a year.

author icon

Editorial independence

Editorial independence means being able to give an unbiased verdict about a product or company, with the avoidance of conflicts of interest. To ensure this is possible, every member of the editorial staff follows a clear code of conduct.

author icon

Professional conduct

We also expect our journalists to follow clear ethical standards in their work. Our staff members must strive for honesty and accuracy in everything they do. We follow the IPSO Editors’ code of practice to underpin these standards.

Trusted Reviews Logo

Sign up to our newsletter

Get the best of Trusted Reviews delivered right to your inbox.

This is a test error message with some extra words