Apple Watch 40mm vs. 44mm: Which Apple Watch size should you get?

The size difference in Apple's various Apple Watch models is subtle, but not so much that you shouldn't think very carefully about making a decision.

So what's the difference? Broadly speaking, the watches are identical save for their horizontal (and vertical size), but that larger chassis does yield some benefits. A slightly bigger watch means a bigger battery, so more battery life. There's also a larger screen which makes reading and typing on your watch face that much easier. However, a larger chassis is going to be heavier and more intrusive on your wrist. For those with skinnier, more slender wrists and forearms, a larger watch might look out of place. If you have larger forearms, a small watch will look comically small. 

Here's everything you need to know about 40mm vs 44mm Apple Watch models.

Apple Watch 40mm vs. 44mm: Time to compare

Unlike traditional watches, which measure case size horizontally, Apple measures the Apple Watch vertically. The two models in question here measure 40mm and 44mm in height and are 34mm and 38mm wide respectively. 

The size differences between the Apple Watch SE, Apple Watch Series 4, Apple Watch Series 5, and Apple Watch Series 6 models might not sound like very much — but the extra 4mm in case size nets you a 28% larger screen. 

The rounded rectangular shape of the Apple Watch makes it hard to compare directly with your average round watch. Still, neither of the Apple Watches would be considered overly wide or high in the traditional watch world. Big watches are typically closer to 45mm wide.

Even if you think you want to go small, you can still consider both sizes — neither is enormous — though those with smaller wrists may find the 40mm fits more comfortably.

The Apple Watch SE, Apple Watch Series 4, Apple Watch Series 5, and Apple Watch Series 6's two case sizes also translate to two different display sizes. Both are Retina-quality, which means the pixels are invisible to the naked eye at normal viewing distance. The bigger Apple Watch simply has more of those pixels:

• The 40mm Apple Watch has a display size of 394x324 pixels
• The 44mm Apple Watch has a display size of 448x368 pixels

When it comes to picking pixel density with Apple Watch 40mm vs. 44mm, watchOS will fill whatever size display you choose, and for many people, it won't make any difference. That said, if you want more pixels, which translates into bigger text and images, it's worth considering the larger option

Apple Watch 40mm vs 44mm: Depth 

Unlike the Watch's two height options and two display densities, there's no difference when it comes to the thickness (or thinness) of the Apple Watch 40mm vs. 44mm, both measure 10.7mm. 

That's because, unlike traditional mechanical or digital watches, the Apple Watch case has to hold a Retina display, the system-in-a-package (chipset), a battery, and sensors. If you're trying to figure out which Apple Watch will best fit under the tight cuffs of your shirt, they're both about the same.

Apple Watch 40mm vs. 44mm: His and hers?

Because there are two sizes, and because some of Apple's bands are unique to one size or another, some have tried to simplify the size discussion down to "hers" and "his."

People come in all shapes and sizes, though, and so do tastes. Some women will want the bigger Apple Watch, and some men, the smaller one. Some people with small wrists will want the bigger watch and vice versa.

All this to say — get the size you prefer. Try both on, and see which one better fits your wrist, style, and personality. That's why Apple has sizes, after all, and why both sizes come with identical features.

Apple Watch 40mm vs. 44mm: Band Bias

Nearly all Apple Watch bands fit their respective Apple Watch sizes. For example, a "small" Apple Watch band that works with an older 38mm watch will also fit a "small" variant of the larger-sized models, the 40mm and the 41mm models now available. Likewise, a band from an old "large" model, the 42mm, model, will fit a 44mm or a 45mm model. You can't use a "small" band with a "large" watch and vice versa, however, otherwise, there is no difference in which bands you can use based on choosing the 40mm or 44mm Apple Watch. Apple boasts a broad array of sport loops and bands, Nike and Hermès, stainless steel, and more in both. 

Apple Watch 40mm vs. 44mm: Battery life

The 44mm Apple Watch SE, Apple Watch Series 4, Apple Watch Series 5, and Apple Watch Series 6 have a slightly bigger battery than the 40mm watch due to more room in the casing. If battery life is most important to you, this is something to consider.

Apple Watch 40mm vs 44mm: Weight 

Naturally, being different sizes, the 40mm and 44mm Apple Watch cases are different weights. The 40mm GPS and GPS + Cellular versions weigh 26.4g and 27.8g respectively, while the 44mm versions are 32.9 and 33g respectively, that's a difference of more than 10%!

Apple Watch 40mm vs. 44mm: Which should you buy?

So while there are some advantages and disadvantages between the 40mm and 44mm Apple Watch models, they are largely negligible and the decision between the two should really come down to personal taste. While the larger one has a clearer screen and slightly better battery life, the smaller version is a bit lighter and also cheaper. In the end, the biggest factor will be which feels better and more comfortable on your wrist.