If you’re shopping for a laptop or just trying to find a sleeve that actually fits, you’ve probably asked: how many inches is a MacBook Air? It sounds like a simple question. But honestly, it’s kinda complicated because Apple isn’t exactly "rounding to the nearest whole number" here.
Most people just say "the 13-inch" or "the 15-inch," but if you pull out a tape measure, you’re going to be surprised. Apple’s latest M4 models, released in 2025, actually have very specific fractional sizes that matter for screen real estate and portability.
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The current lineup: 13.6 vs 15.3 inches
Basically, if you walk into an Apple Store today, you aren't getting a flat 13-inch screen. The standard small MacBook Air is actually 13.6 inches. This changed back when the M2 model launched with the "notch" design, and it has stayed that way through the M3 and the brand-new M4 generations.
Then you’ve got the big brother. The 15-inch MacBook Air is actually 15.3 inches.
Why the weird decimals? Apple measures these diagonally, corner to corner. But there’s a catch: they also have rounded corners at the top. If you were to measure the screen as a perfect, sharp-edged rectangle, you’d get that 13.6 or 15.3 figure. Because of those rounded corners and the camera notch, the actual viewable area is technically a tiny bit less.
Why the size jump happened
For years, the MacBook Air was stuck at 13.3 inches. It was the gold standard. However, when Apple ditched the old tapered "wedge" design for the flatter, more modern look, they pushed the screen further toward the edges. They shrunk the bezels (the black borders) and added the notch for the camera.
This allowed them to squeeze an extra 0.3 inches of screen out of roughly the same footprint. It doesn’t sound like much, but when you're trying to fit two browser windows side-by-side, you definitely feel it.
Physical dimensions: It’s not just about the screen
When you’re wondering how many inches is a MacBook Air, you might actually be thinking about your backpack. A 13-inch screen doesn't mean the laptop is 13 inches wide.
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Let's look at the 13-inch M4 model's physical footprint:
- Width: 11.97 inches
- Depth (front to back): 8.46 inches
- Thickness: 0.44 inches
Compare that to the 15-inch model:
- Width: 13.40 inches
- Depth: 9.35 inches
- Thickness: 0.45 inches
The 15-inch version is surprisingly thin—nearly the same as the smaller one—but it’s significantly wider. If you use a standard commuter backpack, the 13.6-inch model slides in like a notebook. The 15.3-inch model is much more of a "I need a dedicated laptop compartment" situation.
Looking back: The 11-inch and 13.3-inch eras
Older models are still all over the used market and sites like Back Market or eBay. If you have an M1 MacBook Air (the one without the notch), your screen is 13.3 inches. That was the standard for over a decade.
And let's not forget the tiny legend: the 11-inch MacBook Air. It actually had an 11.6-inch screen. Apple killed it off in 2016, but some people still swear by it for travel. It was basically the size of an iPad with a keyboard attached.
There was also a 12-inch MacBook (not an "Air," just "MacBook") that lived briefly from 2015 to 2019. It was incredibly portable but famously underpowered. Nowadays, the 13.6-inch Air has effectively replaced all these smaller variants because the bezels are so much thinner.
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Which size is actually better for you?
Choosing between 13.6 and 15.3 inches usually comes down to how you work.
The 13-inch is the "pro-traveler" choice. It’s light (2.7 pounds) and fits on those tiny economy airplane trays. If you’re a student or someone who hops between coffee shops, this is usually the sweet spot.
The 15-inch is for the "no-external-monitor" crowd. If you do your work entirely on the laptop screen without plugging into a big display at home, the 15.3-inch Liquid Retina display is a lifesaver. You get more rows in Excel and more room for your timeline in Final Cut. Plus, the 15-inch has a six-speaker sound system with force-cancelling woofers, whereas the 13-inch only has four speakers. The sound is noticeably "fuller" on the bigger machine.
How to measure your own MacBook Air
If you’ve got a laptop in front of you and aren't sure which one it is, don't measure the metal casing.
- Grab a measuring tape.
- Start at the bottom-left corner of the actual glass display area (not the metal frame).
- Pull it diagonally to the top-right corner.
- If it’s around 13.3 or 13.6, you’ve got the small one. If it’s over 15, you’ve got the big one.
Alternatively, you can just click the Apple Menu () in the top left corner of your screen and select About This Mac. It will literally tell you the year and size right there, like "MacBook Air (15-inch, M3, 2024)."
Summary of sizes for 2026
- MacBook Air M4 (2025/2026): 13.6-inch or 15.3-inch options.
- MacBook Air M3 (2024): 13.6-inch or 15.3-inch options.
- MacBook Air M2 (2022/2023): 13.6-inch or 15.3-inch options.
- MacBook Air M1 (2020): 13.3-inch only.
- Intel MacBook Air (2018-2020): 13.3-inch.
- Legacy MacBook Air (Pre-2018): 13.3-inch or 11.6-inch.
When buying accessories, always check the "M" generation or the specific decimal size. A sleeve made for the old 13.3-inch M1 might be a little tight or weirdly loose on the newer 13.6-inch M4 because the chassis shape changed from a wedge to a flat slab.
For the best experience, match your bag or case to the specific year of your model rather than just the "inches" advertised on the box. If you're buying new today, go to a store and feel the weight difference between the 2.7-pound 13-inch and the 3.3-pound 15-inch; that half-pound feels like a lot more than it sounds after an hour of carrying it.