How to Measure Your Laptop: MacBook Sizes & Sleeve Choices
A laptop sleeve should match the closed computer, the accessories you carry and the bag it travels in. Start with the exact model and its body dimensions; then choose the carry style. A display label such as 13-inch or 14-inch is only a starting point.
Quick choice for a 14-inch MacBook Pro: if your laptop usually rides inside a backpack, start with a slim sleeve such as Shield-A18. For short hand-carry trips with a front pocket and retractable handle, compare Shield-A17. For a shoulder strap and a fuller work kit, start with Carry-A20. The size checks below come before the style decision.
Jump to MacBook measurements, measuring your laptop, reading a bag size chart or SENLASI style recommendations.
MacBook body dimensions: match the generation first
Find the model name, chip and year under Apple menu → About This Mac. These measurements describe the bare, closed computer, without a snap-on shell. The order is always width × depth × thickness. Use the millimetre figures for calculations; the inch figures below are Apple's rounded published values.
| Exact model group | Width × depth × thickness |
|---|---|
| MacBook Air 13-inch M2 (2022), M3 (2024), M4 (2025) | 304.1 × 215 × 11.3 mm 11.97 × 8.46 × 0.44 in |
| MacBook Air 15-inch M2 (2023), M3 (2024), M4 (2025) | 340.4 × 237.6 × 11.5 mm 13.40 × 9.35 × 0.45 in |
| MacBook Pro 13-inch M2 (2022) | 304.1 × 212.4 × 15.6 mm 11.97 × 8.36 × 0.61 in |
| MacBook Pro 14-inch M4, M4 Pro or M4 Max (2024) | 312.6 × 221.2 × 15.5 mm 12.31 × 8.71 × 0.61 in |
| MacBook Pro 16-inch M4 Pro or M4 Max (2024) | 355.7 × 248.1 × 16.8 mm 14.01 × 9.77 × 0.66 in |
The chart covers only the generations named above. An older Intel model, M1 Air or a later model needs its own specification check. Screen diagonal and body width are different measurements: a 13-inch computer is not necessarily 13 inches wide.
Three comparisons that change what you should buy
- 13-inch Air versus 13-inch Pro M2: both are 304.1 mm wide, but the Air is 2.6 mm deeper and the Pro is 4.3 mm thicker. A very close-fitting sleeve made for one body should not be assumed to fit the other.
- 14-inch Pro versus 15-inch Air in this chart: the Air is 27.8 mm wider and 16.4 mm deeper, even though it is thinner. Extra thickness room cannot compensate for a sleeve that is too narrow.
- 15-inch Air versus 16-inch Pro in this chart: the Pro adds 15.3 mm in width, 10.5 mm in depth and 5.3 mm in thickness. Do not choose a 15-inch Air sleeve for a 16-inch Pro just because the screen labels are close.
Measure the laptop as you actually carry it
Use a rigid ruler or a tape measure held straight on a flat desk. Close the lid and disconnect the charger, USB receivers and other plugs. If you keep a hard shell fitted for travel, leave that shell on for all three measurements.
- Width: measure left to right across the widest part of the closed body, including any shell corners.
- Depth: measure front to back, including a hinge or shell lip that extends beyond the main body.
- Thickness: measure at the thickest point, including raised feet. A wedge-shaped computer should not be measured only at its thin front edge.
Write the result in one unit. One inch equals 25.4 mm. Do not round down to make a laptop fit a size limit. For Windows laptops, record the full model number as well: two laptops sold with the same display diagonal can have different footprints and hinges.
A hard shell changes the relevant numbers. The Air M4 13-inch body starts at 304.1 × 215 × 11.3 mm, but adding a shell does not have a standard allowance. Measure the assembled computer rather than adding a guessed 2 or 3 mm to Apple's specification.
Which bag dimensions should you compare?
| Label | What it helps you decide |
|---|---|
| Maximum device size or named compatibility | Whether your specific computer is an intended match. Check the exact model or all three stated limits. |
| Internal dimensions | The stated space inside the laptop compartment. The zipper opening, seams and corner shape can still affect insertion. |
| External dimensions | Whether the sleeve itself fits your backpack or tote. Padding and pockets are included; these figures do not establish laptop fit. |
For the SENLASI listings compared here: the A17 and A18 14-inch pages show 35.6 × 25 × 2.3 cm as reference fit/dimensions. That wording does not identify a measured internal compartment, so do not use it to calculate spare space around your MacBook. Their pages target 14-inch MacBook Pro; for a different model or a hard shell, confirm the usable compartment and opening before ordering.
When a seller does provide a confirmed maximum device size, compare each axis separately. If any laptop dimension exceeds its limit, rule that option out. If all are within the limits, also check the stated model compatibility and closure design. There is no universal rule to add exactly 1 cm to every laptop: too much space can allow movement, while a tight opening can make a numerically plausible fit awkward.
For carry inside another bag, do a second comparison using the sleeve's outside dimensions and your backpack's usable compartment. Include its opening: a compartment can be wide enough at the bottom but too narrow at the zipper.
Which SENLASI style should you shortlist?
The three links below open the 14-inch MacBook Pro versions so you can compare like with like. These are recommendations based on the listed design and your carry routine, rather than a hands-on protection ranking.
| Style | Choose it when… / reconsider when… |
|---|---|
| Shield-A18 sleeve | Your laptop mainly goes inside a backpack or tote. It has a carry handle, accessory storage, padded construction and a velvet lining. Reconsider a slim sleeve when a bulky charger and mouse need to travel in the same compact package. |
| Shield-A17 briefcase | You want a retractable handle and front pocket for a short trip between car, office and meetings. It is still a slim format: choose according to the actual accessory load, not the word briefcase alone. |
| Carry-A20 shoulder bag | You want shoulder carry and room for a fuller daily kit, including documents. The strap and roomier briefcase shape make it the first comparison for a walking commute; reconsider it if minimum bulk inside another bag is your priority. |
Put the recommendation into a real shopping decision
Backpack commuter with a 14-inch Pro: start with A18 if your main bag already organizes the charger and other items. Choose the sleeve for the computer, then check that the sleeved computer fits the backpack opening. Packing a large adapter into the sleeve pocket can undo the benefit of a slim profile.
Short meetings with a 14-inch Pro: compare A17 if you want to carry the computer by its retractable handle and keep a few essentials together. If your daily walk is long enough that hand carry becomes inconvenient, move the comparison to A20 for its shoulder strap.
15-inch Air owner: start with a dedicated 15-inch version, such as the A18 15-inch listing, then confirm your generation. Do not choose the 14-inch Pro version from the table simply because the Air is thinner. For a 13-inch Air or Pro, begin with the A18 13–13.5-inch listing and apply the Air-versus-Pro depth and thickness comparison above.
Check these five things before discarding the packaging
- The delivered size and product model match the version you ordered.
- The closed, unplugged laptop slides in without forcing the opening.
- The zipper closes without pressing down on the lid or pulling hard around the corners.
- Your normal accessories sit in their intended pocket without making a hard bulge against the computer.
- The complete sleeve fits your main bag and the laptop does not move excessively inside it.
If a fit feels forced, do not stretch the sleeve around the device. Recheck the model and measurements before using it for your daily carry. Ready to compare options? Browse 14-inch MacBook Pro carry options or the full laptop sleeve collection.
Measurement sources
Apple's technical specifications supply the device measurements: Air 13-inch M4, Air 15-inch M4, Pro 13-inch M2, Pro 14-inch M4, Pro 14-inch M4 Pro/Max and Pro 16-inch M4 Pro/Max. For earlier Air generations in the table, see Air 13-inch M2 (2022), Air 13-inch M3 (2024), Air 15-inch M2 (2023), Air 15-inch M3 (2024). Product features were checked on the linked SENLASI listings on September 29, 2026.