Can Apple Watch Measure Oxygen Level? Here’s the Real Truth

If you’ve ever wondered, can Apple Watch measure oxygen level, you’re not alone.

Since the launch of the Blood Oxygen app, people everywhere—from hikers to health nuts—have been curious whether the Apple Watch is more than just a sleek wrist computer.

The answer is yes, it can.

But there’s a lot more you need to know before you start trusting your watch with your wellness data.

This guide breaks it all down: how it works, which models support it, what it measures, how accurate it is, and more.

• Key Takeaways

• Can Apple Watch Measure Oxygen Level?

• How Apple Watch Blood Oxygen Monitoring Works

• What Is Blood Oxygen and Why It Matters

• Supported Apple Watch Models for Measuring Oxygen Level

• How to Set Up the Blood Oxygen App on Apple Watch

• How to Take a Blood Oxygen Reading Manually

• How Accurate Is the Apple Watch Oxygen Sensor?

• Can Apple Watch Detect Sleep Apnea or COVID Symptoms?

• Best Practices for Accurate SpO2 Readings

• Blood Oxygen vs Heart Rate vs ECG on Apple Watch

• Apple Watch Blood Oxygen Monitoring in Real Life

• Is Apple Watch Blood Oxygen Monitoring Safe to Use?

• Limitations of Apple Watch Oxygen Monitoring

• Future of Blood Oxygen Tracking on Smartwatches

• FAQs

• Summary: So, Can Apple Watch Measure Oxygen Level?

Key Takeaways

• Yes, Apple Watch measures oxygen levels using the Blood Oxygen app.

• This feature is only available on Apple Watch Series 6 and later.

• It uses red and infrared LEDs to estimate SpO2 levels.

• While not medically certified, it’s useful for tracking wellness trends.

• Accuracy can vary based on movement, wrist fit, and skin tone.

Can Apple Watch Measure Oxygen Level?

Absolutely, it can.

Apple introduced the Blood Oxygen feature in the Apple Watch Series 6 and continued it in all newer models like Series 7, 8, 9, and Ultra.

Using built-in infrared and red LED sensors, your watch estimates your blood oxygen saturation (SpO2) level—showing you how well your body is circulating oxygen.

This measurement is shown as a percentage, and typically, healthy levels fall between 95% and 100%.

Apple Watch doesn’t just give on-demand readings; it also takes background measurements while you’re resting or asleep.

For a full walkthrough, check Apple’s official guide:
Apple Blood Oxygen App

How Apple Watch Blood Oxygen Monitoring Works

So, how exactly does the Apple Watch read oxygen levels through your skin?

It’s all about light.

The back of the watch houses special sensors that shine red and infrared light into your wrist.

Your blood absorbs different wavelengths of this light depending on how much oxygen it contains.

The reflected light is captured by photodiodes and used to calculate your SpO2 level—a non-invasive, passive technique that mimics how pulse oximeters work.

These readings are stored in the Health app on your iPhone, allowing you to monitor trends over time.

What Is Blood Oxygen and Why It Matters

Your blood oxygen level reflects how efficiently oxygen is moving from your lungs to the rest of your body.

When blood oxygen is too low—known as hypoxemia—it can be a sign of:

• Sleep apnea

• Lung disease

• COVID-19 or other respiratory infections

• High-altitude sickness

For athletes, travelers, and people with chronic health conditions, SpO2 tracking is a great way to stay on top of general wellness.

Although it’s not a diagnostic tool, the Apple Watch offers helpful insights into your body’s internal performance.

Supported Apple Watch Models for Measuring Oxygen Level

Not every Apple Watch can check blood oxygen levels.

Here are the models that do support this feature:

Still not sure what model you’re wearing?
Use this complete Apple Watch model guide to find out.

And if you’re considering an upgrade, here’s a rundown of the best Apple Watch options.

How to Set Up the Blood Oxygen App on Apple Watch

Setting up is simple.

1. Make sure your iPhone is updated to the latest iOS.

2. Open the Health app, tap Browse > Respiratory > Blood Oxygen.

3. Select Set Up Blood Oxygen and follow the instructions.

4. On your Apple Watch, go to Settings > Blood Oxygen.

5. Enable both “Allow Blood Oxygen Measurements” and “In Sleep Mode.”

Once activated, your Apple Watch will begin taking automatic background readings throughout the day and night.

How to Take a Blood Oxygen Reading Manually

Want a live reading?

Here’s how:

1. Rest your arm flat on a table and keep still.

2. Open the Blood Oxygen app on your Apple Watch.

3. Tap Start, wait about 15 seconds, and check your result.

Keep in mind, movement, tattoos, and even room temperature can affect accuracy.

Using a snug, comfortable band—like one of these top-rated Apple Watch bands—can make a big difference.

How Accurate Is the Apple Watch Oxygen Sensor?

Apple Watch does a solid job estimating oxygen levels—but it’s not flawless.

It’s important to know the Blood Oxygen app is not FDA-cleared and isn’t meant for medical use.

That said, it’s surprisingly accurate when used correctly.

Tests from sources like CNET show Apple Watch readings are usually within 1-2% of medical-grade oximeters.

However, some factors can skew results:

• Dark tattoos on the wrist

• Loose watch bands

• Movement during readings

• Cold temperatures or poor circulation

Use the feature consistently, and you’ll see reliable wellness trends over time—even if individual readings vary slightly.

Can Apple Watch Detect Sleep Apnea or COVID Symptoms?

Technically, no.

Your Apple Watch won’t alert you to low oxygen during sleep or diagnose COVID-19.

However, it can spot patterns that might signal issues, like:

• Overnight SpO2 drops

• Persistent low oxygen levels

• Unusual fluctuations

Several users have reported discovering health problems thanks to this data.

But again—Apple makes it clear this feature is for general wellness, not diagnosis or medical treatment.

Best Practices for Accurate SpO2 Readings

If you want the best results from your Apple Watch, follow these guidelines:

• Wear your watch snug, just above the wrist bone.

• Use Apple’s Sport Loop or Solo Loop bands for a secure fit.

• Avoid taking readings during exercise or while moving.

• Make sure the sensor area is clean and dry.

• Measure in a warm, well-lit environment.

Want the most accurate results during sleep?
Check out this list of Series 9-compatible bands for sleep tracking.

Blood Oxygen vs Heart Rate vs ECG on Apple Watch

Apple Watch tracks more than just oxygen.

Together, these features give you a powerful toolkit for monitoring everything from stress to heart health.

Use them in combination for a fuller picture of your body’s performance.

Apple Watch Blood Oxygen Monitoring in Real Life

Many users use the Blood Oxygen app in everyday life:

• Hikers track oxygen at high altitudes

• Sleep apnea sufferers watch overnight trends

• Long COVID patients monitor respiratory recovery

• Athletes use it to track conditioning and performance

Forums like Reddit are full of stories about people who spotted unusual patterns in their readings and took action.

It’s not a medical tool, but it can definitely support smarter health choices.

Is Apple Watch Blood Oxygen Monitoring Safe to Use?

Yes, it’s totally safe.

The sensors use non-invasive light and don’t emit radiation.

There are no risks from taking too many readings.

Apple emphasizes this tool is for wellness only, and isn’t a substitute for proper medical tests.

But used responsibly, it’s an excellent addition to your health routine.

Limitations of Apple Watch Oxygen Monitoring

There are a few things your Apple Watch can’t do:

• It won’t alert you to dangerously low oxygen levels.

• It doesn’t track oxygen continuously 24/7.

• It’s not approved by the FDA.

• Factors like tattoos or wrist motion can distort results.

Despite those limitations, it’s still one of the most convenient, tech-forward ways to stay in tune with your body.

Future of Blood Oxygen Tracking on Smartwatches

The future is bright for wearable health tech.

Rumors suggest Apple is pushing toward FDA approval for future models.

Other smartwatches like Fitbit, Samsung Galaxy Watch, and Garmin already offer similar features.

Expect to see:

• Continuous monitoring

• AI-powered health alerts

• Advanced respiratory analysis

Blood oxygen tracking is just the beginning.

✅ External Links (Authoritative Sources)

1. Apple Support – Blood Oxygen App Overview
   https://support.apple.com/en-us/HT211027
   → Use this link when explaining how Apple Watch reads blood oxygen or in the setup section.

2. CNET – Apple Watch Blood Oxygen Accuracy Review
   https://www.cnet.com/health/apple-watch-blood-oxygen-monitor/
   → Great for discussing real-world accuracy compared to medical-grade oximeters.

3. Medical News Today – Can Apple Watch Measure Blood Oxygen?
   https://www.medicalnewstoday.com/articles/apple-watch-oxygen
   → Perfect reference when discussing limitations and health claims.

📺 Relevant YouTube Videos

1. How to Use the Blood Oxygen App on Apple Watch Series 8
   https://www.youtube.com/watch?v=Hyh2s7nE3ew
   

2. How to Use Blood Oxygen App on Apple Watch Series 6
   How to Use Blood Oxygen App on Apple Watch Series 6
   

3. A Doctor's Take On Apple's "Blood Oxygen" Sensor
   https://www.youtube.com/watch?v=D0ayF9Kza9E
   

FAQs

Can Apple Watch measure oxygen level while sleeping?

Yes, if background measurements are enabled in the Health app settings.

Which Apple Watch has the oxygen sensor?

Series 6 and newer models support it, including both versions of the Apple Watch Ultra.

Why is my Apple Watch not measuring blood oxygen?

Make sure you have a supported model, the feature is turned on, and your band is snug. Tattoos or motion may affect accuracy.

Can I use Apple Watch blood oxygen readings for medical diagnosis?

No. Apple clearly states this feature is for wellness tracking, not medical use.

How often does Apple Watch measure blood oxygen?

It takes readings periodically in the background, plus anytime you initiate one manually via the Blood Oxygen app.

Summary: So, Can Apple Watch Measure Oxygen Level?

Yes, your Apple Watch can absolutely measure oxygen level—but only if you have the right model.

It’s a powerful wellness feature that gives insight into how your body delivers oxygen, especially useful for:

• Athletes

• Sleep tracking

• High-altitude activities

• General health awareness

While it’s not a replacement for medical equipment, it’s a useful tool that fits comfortably on your wrist.

And when used correctly, it can become one of the most insightful health features Apple offers today.

Blog Author section.

Emily Johnson

 

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Emily is a seasoned writer and technology enthusiast with a passion for digital watches and wearable tech. With over a decade of experience in the tech industry, she brings a wealth of knowledge and insights to her readers.