Apple Watch Series 7 Sizes

How to Determine Your Apple Watch Size

Understanding Your Apple Watch

The Apple Watch, a marvel of modern technology, comes in a variety of sizes.

From the compact 38mm to the more substantial 45mm, there’s an Apple Watch size to suit every wrist.

Apple Watch SizeDimensions (mm)
38mm38 x 33.3
40mm40 x 34
42mm42 x 35.9
44mm44 x 38.6
45mm45 x 37.5

But here’s the million-dollar question: how to tell what size Apple Watch you have?

Well, you’re in luck because we’re about to dive into that very topic.

In our article Apple Watch Sizes Explained: 41mm vs 45mm, we’ve already touched on the different sizes available.

But knowing the size of your own Apple Watch is a different ball game.

Why, you ask?

Well, it’s not just about bragging rights.

Knowing your Apple Watch size can help you make informed decisions about band replacements, screen protectors, and even potential upgrades.

For a more detailed guide on identifying your Apple Watch model, check out this comprehensive guide from Apple Support.

Why Size Matters

No, we’re not just talking about aesthetics here.

Apple Watch on a wrist with stylish accessories

Now, let’s talk about why size matters.

The size of your Apple Watch can significantly impact your user experience.

AspectImpact of Wrong Size
ComfortClunky and uncomfortable feel (if too big) or poor visibility (if too small)
Health Tracking AccuracyInaccurate heart rate readings (if too loose) or restricted blood flow (if too tight)

A watch that’s too big can feel clunky and uncomfortable, while one that’s too small might not offer the best visibility.

In other words, size matters when it comes to comfort and functionality.

But there’s more.

The size of your Apple Watch can also affect the accuracy of health tracking features.

For instance, a watch that’s too loose might not provide accurate heart rate readings.

On the flip side, a watch that’s too tight might restrict blood flow, leading to uncomfortable wear and potentially skewed health data.

Don’t just take our word for it.

Check out this insightful article from Nereides Blog that delves into the importance of finding the right Apple Watch size.

In conclusion, knowing your Apple Watch size is not just a trivial fact.

It’s an essential piece of information that can enhance your overall Apple Watch experience.

Checking the Back of Your Apple Watch

Let’s start with the simplest method to determine your Apple Watch size: checking the back of your watch.

Yes, you heard it right.

The answer to the question, “how to tell what size Apple Watch you have” might be right under your nose, or in this case, on your wrist.

Flip your Apple Watch and take a look at the back.

You’ll see some text around the heart rate sensor.

Among other things, this text includes the size of your Apple Watch.

It’s usually in millimeters (mm), like 38mm, 40mm, 42mm, 44mm, or 45mm.

If you’re having trouble seeing the small text, don’t worry.

You can use your iPhone’s camera to zoom in or use a magnifying glass if you have one handy.

For a more detailed guide on identifying your Apple Watch, check out this WikiHow Guide.

Using the Apple Watch App

If for some reason you can’t find the size on the back of your watch, there’s another way.

You can use the Apple Watch app on your iPhone.

Model Number Starts WithApple Watch Size
M38mm or 40mm
L42mm, 44mm, or 45mm

Apple Watch with customizable watch faces

Here’s how:

  1. Open the Apple Watch app on your iPhone.
  2. Tap on ‘My Watch’ at the bottom of the screen.
  3. Then tap on ‘General’.
  4. Finally, tap on ‘About’.

In the ‘About’ section, you’ll find a wealth of information about your Apple Watch, including the model number.

The first character of the model number indicates the size of your Apple Watch.

For instance, if the model number starts with ‘M’, it’s a 38mm or 40mm model.

If it starts with ‘L’, it’s a 42mm, 44mm, or 45mm model.

Remember, knowing how to unlock your Apple Watch can be crucial in accessing this information.

If you’re unsure about this, our guide on How to Unlock Your Apple Watch Without a Passcode can be a lifesaver.

For more insights on identifying your Apple Watch model, this article from iPhone Life is a great resource.

So, there you have it.

Two simple ways to tell what size Apple Watch you have.

Remember, whether it’s on your wrist or in the app, the answer is just a few taps away.

Additional Tips to Determine Your Apple Watch Size

So, you’ve checked the back of your Apple Watch and used the app, but you’re still not sure about the size?

Don’t worry, we’ve got another trick up our sleeve.

You can use your Apple Watch’s serial number to determine its size.

Yes, you read that right.

Your Apple Watch’s serial number is more than just a random string of characters.

It’s a treasure trove of information, including the size of your watch.

To find your serial number, you can either check the back of your watch or go to the ‘About’ section in the Apple Watch app on your iPhone.

Once you have the serial number, you can use a trusted online resource like Flipsy to determine the size of your Apple Watch.

Choosing the Right Apple Watch Size for You

Now that you know how to tell what size Apple Watch you have, let’s talk about choosing the right size when buying a new one.

Choosing the right size is not just about the fit.

Apple Watch with health and fitness features showcased

It’s also about how the watch looks on your wrist and how comfortable it feels throughout the day.

For instance, if you have a smaller wrist, a 38mm or 40mm Apple Watch might be a better fit.

On the other hand, if you have a larger wrist, a 42mm, 44mm, or 45mm model might be more suitable.

Our guide on Comparing Apple Watch Series 3 Sizes: Which is Right for You? can provide more insights on this topic.

For more tips on choosing the right Apple Watch size, check out this article from Switching To Mac.

Wrapping Up

So, there you have it.

A comprehensive guide on how to tell what size Apple Watch you have.

From checking the back of your watch to using the Apple Watch app and even your serial number, we’ve covered all the bases.

We’ve also discussed the importance of choosing the right size when buying a new Apple Watch.

Remember, the right size can enhance your comfort, functionality, and overall user experience.

So, the next time someone asks you, “What size is your Apple Watch?” you’ll know exactly what to say.

And don’t forget to explore more Apple Watch-related content on our website.

We’ve got a wealth of information to help you get the most out of your Apple Watch.

Happy sizing!


What are the different sizes of Apple Watches available?

  • Apple Watch Series 4, 5, 6, and 7 come in two sizes: 40mm and 44mm.
  • Apple Watch SE is available in two sizes: 40mm and 44mm.
  • Older models, such as Apple Watch Series 1, 2, and 3, come in 38mm and 42mm sizes.

How can I tell what size Apple Watch I have?

  • On the back of your Apple Watch, you’ll find a small text that indicates the case size (e.g., 40mm or 44mm).
  • If you have the original packaging, the size is mentioned on the label or the box.
  • Alternatively, you can measure the height of your Apple Watch’s screen to determine the size. A 40mm screen measures about 33mm, while a 44mm screen measures around 38mm.

Can I use bands interchangeably between different-sized Apple Watches?

  • Yes, you can use bands interchangeably between Apple Watches of the same size. For example, a 40mm band can fit any 40mm Apple Watch.
  • Similarly, a 44mm band is compatible with any 44mm Apple Watch.

Are the features the same on both Apple Watch sizes?

  • Yes, the features and functionality of the Apple Watch are the same regardless of the size you choose.
  • The only difference lies in the screen and case size, which affects the overall dimensions and weight.

Can I exchange or return my Apple Watch if I buy the wrong size?

  • Yes, Apple offers a return policy that allows you to exchange or return your Apple Watch within a specified period (usually 14 days).
  • Ensure you review the return policy and guidelines on the Apple website or contact their customer support for further assistance.

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