A sleeve that is too small will not close, and one that is too big lets the laptop slide about and knock its corners, which is the damage a sleeve is meant to prevent. The label on a sleeve is a screen size, but a sleeve has to fit the whole laptop, and laptops with the same screen size can differ by a couple of centimetres in width or depth. This guide explains why, shows how to measure your laptop properly, and goes through the common sizes, MacBooks and other thin laptops, and how snug a sleeve should be.
Why screen size is not the whole story
A laptop's screen size is measured diagonally across the screen, from one corner to the opposite corner, in inches. One inch is exactly 2.54 cm. So a 15.6-inch laptop has a screen about 39.6 cm across the diagonal. That number is useful for knowing which size class a laptop belongs to, but three other things decide how big the laptop actually is.
The shape of the screen
Screens come in different shapes. Many laptops have a 16:9 screen, the same shape as a television, which is wide and fairly short. Many newer laptops have a 16:10 screen, which is a little taller for the same width, and some, such as Microsoft's Surface Laptop, have a 3:2 screen, which is taller again. For the same diagonal, a taller screen is narrower and deeper. That is why a 16-inch laptop is often deeper from front to back than a 15.6-inch one, and why two "14-inch" laptops can need different sleeves.
The border around the screen
The screen sits inside a frame, often called the bezel, and the lid around it is bigger than the screen itself. Thin borders make a laptop smaller for its screen size. A laptop with thick borders, or with a large hinge, can be a centimetre or two bigger in each direction than a slim one with the same screen.
Thickness
Thin laptops are a little over a centimetre thick with the lid closed. Gaming and workstation laptops are much thicker, and often heavier, with bigger vents and sometimes a raised section at the back. A sleeve has to go round that thickness too, so a thick laptop needs a deeper sleeve than its screen size suggests.
Rounded corners and screen cut-outs
Some makers measure the screen as if it were a plain rectangle, even when the corners are rounded. Apple says, for example, that its MacBook screens have rounded corners at the top, that the size is measured as a standard rectangular shape, and that the actual viewable area is less. It makes no difference to fitting a sleeve, but it explains why a "13-inch" MacBook Air is listed with a 13.6-inch screen.
How to measure width, depth and thickness
The quickest way is to look up your laptop's measurements on the maker's own specifications page. To find the exact model on a Mac, open the Apple menu and choose About This Mac. On Windows, open Settings, then System, then About, where the model name is shown under the device name. Search for that name with the word specifications and use the maker's own page, not a shop listing.
If you cannot find the figures, or you want to check them, measure the laptop yourself. It takes two minutes.
- Close the lid and put the laptop on a flat table.
- Use a tape measure or a long ruler in centimetres.
- Measure the width from side to side at the widest point. Include any part of the hinge that sticks out.
- Measure the depth from the front edge to the back edge. Include any bumps or vents at the back.
- Measure the thickness at the thickest point, usually near the hinge, with the laptop sitting on its feet. Include the feet.
- If you keep the laptop in a hard-shell case, leave it on and measure the laptop with the shell.
- Round each number up to the next half centimetre.
Then compare your three numbers with the sleeve. The figures that matter are the sleeve's inside measurements, if the listing gives them. If it only gives outside measurements, remember that the padding takes up room, so the space inside is smaller than the outside by the thickness of the padding on each side. If a listing gives no measurements at all and only a screen size, use the screen size as a rough guide and expect to be less certain of the fit.
Reading a listing's measurements
Listings give measurements in different ways, and it is worth knowing what each one means before you compare. Some give the inside of the sleeve, which is the number you want. Some give the outside, which includes the padding and any front pocket. Some give the largest laptop the sleeve is made for, often written as "fits laptops up to" a width and depth, which is just as useful as the inside size. A few give only a screen size, which is the least helpful, because, as above, laptops with the same screen size differ.
Measurements are sometimes given in inches. To change inches to centimetres, multiply by 2.54. A sleeve listed as 12.6 by 9 inches inside, for example, is 32 by 22.9 cm. Do the sum for every figure rather than guessing, because a few millimetres decide whether a zip closes.
When you cannot measure the laptop
If the sleeve is a present, or the laptop is somewhere else, you can still find the size. The model name is usually printed on the box, on the receipt or order confirmation, or on a label on the underside of the laptop. For a Mac, Apple explains that the serial number on the underside can be entered on its Check Coverage page to find the model. Once you have the model name, the maker's specifications page will give you the measurements.
A tip worth knowing: measure the thickness properly. People often measure width and depth and forget it, and a sleeve that fits a thin laptop's width can still be too tight to zip round a thick one.
The common sizes, 13 to 17 inch
Laptop sleeves are grouped by the screen sizes laptops are usually sold in. Each group covers a small spread of sizes. The table below shows the size of the screen itself for each common size, worked out from the diagonal and the screen's shape. The laptop will be bigger than its screen by the border and the hinge, but the table shows why shape matters: a taller screen makes a deeper laptop for the same diagonal.
| Screen size | Screen shape | Screen width | Screen height |
|---|---|---|---|
| 13.3-inch | 16:9 | 29.4 cm | 16.6 cm |
| 13.3-inch | 16:10 | 28.6 cm | 17.9 cm |
| 13.8-inch | 3:2 | 29.2 cm | 19.4 cm |
| 14-inch | 16:9 | 31.0 cm | 17.4 cm |
| 14-inch | 16:10 | 30.2 cm | 18.8 cm |
| 15.6-inch | 16:9 | 34.5 cm | 19.4 cm |
| 16-inch | 16:10 | 34.5 cm | 21.5 cm |
| 17.3-inch | 16:9 | 38.3 cm | 21.5 cm |
The screen sizes and shapes in the table are common ones, not a list of every laptop. Use it to understand the sizes, and use your own laptop's measurements to choose.
13-inch
The 13-inch group covers laptops sold as 13-inch and 13.3-inch, and many small laptops with screens a little bigger, such as 13.5 or 13.6 inches, sit close to it. These are the lightest everyday laptops, often thin and easy to carry. A 13-inch laptop sleeve is the place to start, but check the depth if your laptop has a taller screen.
14-inch
14-inch laptops are a popular middle size: a bigger screen than a 13-inch with not much more to carry. Because 14-inch laptops come with both 16:9 and 16:10 screens, they vary more in depth than you might expect. Look at the 14-inch laptop sleeves and compare depth carefully.
15.6-inch
For many years 15.6 inches was the standard size for a family or office laptop, and many still are. They are usually 16:9, so they are wide but not especially deep, and many have a number pad beside the keyboard. A 15.6-inch laptop sleeve also suits most laptops sold as 15-inch.
16-inch
16-inch laptops are often the 15.6-inch laptop's replacement with a taller 16:10 screen. They tend to be about as wide as a 15.6-inch laptop but noticeably deeper, which is why a 15.6-inch sleeve is often too short for them. Choose from the 16-inch laptop sleeves and check the depth.
17-inch
17-inch and 17.3-inch laptops are the largest common size, usually desktop replacements or gaming laptops, and are often thick as well as wide. A 17-inch laptop sleeve needs to allow for that thickness, so check the height figure as well as the width and depth.
MacBooks and other thin laptops
MacBooks are a good example of why the label is not enough. Apple's own specifications pages, as they stood in November 2026, give these measurements for the current models:
| Model | Screen | Width | Depth | Thickness |
|---|---|---|---|---|
| MacBook Air 13-inch | 13.6-inch | 30.41 cm | 21.5 cm | 1.13 cm |
| MacBook Air 15-inch | 15.3-inch | 34.04 cm | 23.76 cm | 1.15 cm |
| MacBook Pro 14-inch | 14.2-inch | 31.26 cm | 22.12 cm | 1.55 cm |
| MacBook Pro 16-inch | 16.2-inch | 35.57 cm | 24.81 cm | 1.68 cm |
A few things stand out. The 14-inch MacBook Pro is only a little wider and deeper than the 13-inch MacBook Air, but it is noticeably thicker, so a sleeve cut closely for the Air may not zip round the Pro. The 16-inch MacBook Pro is 24.81 cm deep, so a sleeve made for a wide but shallower 15.6-inch laptop may be too short for it; check the depth before choosing. Older MacBooks were made in different sizes, so if yours is not a current model, look up your model on Apple's support site, where Apple's page on identifying your MacBook model lists them by year.
For MacBooks there are ranges grouped by model: for MacBook Air 13-inch, for MacBook Air 15-inch, for MacBook Pro 14-inch and for MacBook Pro 16-inch. If you use a hard-shell case, remember it adds to every measurement, so allow for it when choosing a sleeve.
Older and second-hand MacBooks
If you have an older MacBook, or bought one second-hand, check exactly which one it is before choosing a sleeve or a shell. About This Mac in the Apple menu shows the model name. Apple's support pages for identifying a MacBook Air or MacBook Pro list each model with its year, and each model's own technical specifications page gives its size. Shells in particular must match the model and year, because the openings for ports, vents and feet move between models even when the outside size barely changes.
Other thin laptops
Thin Windows laptops and Chromebooks vary more than MacBooks, because there are so many makers and models, and the same name can cover several sizes. Microsoft's Surface Laptop is a useful example of screen shape at work. Microsoft lists the 13.8-inch Surface Laptop (7th Edition) at 301 mm wide, 220 mm deep and 17.5 mm thick, with a 3:2 screen. That makes it about as wide as a 13-inch MacBook Air but a little deeper, and thicker. Accessories for these are grouped for Microsoft Surface and for Chromebooks, but for a sleeve, the measurements are what count.
Thin laptops are the ones where a close fit matters most. A thin laptop in a roomy sleeve slides from end to end every time the bag moves, and its corners take the knocks. Choose a sleeve whose inside measurements are only a little bigger than the laptop.
Snug or roomy: choosing the fit
Once you know the laptop fits, there is still a choice to make about how closely it fits. Neither is wrong. It depends on what else you want the sleeve to do.
A snug fit
A snug sleeve holds the laptop still, adds the least bulk and slips into a bag compartment easily. Neoprene and other stretchy sleeves can be close fitting because they give a little. Firm foam sleeves do not stretch, so a snug one should still let the laptop slide in without forcing the zip round the corners. A sleeve that is so tight you have to wrestle the laptop in and out will strain its zip and may rub the laptop's finish.
A roomier fit
A roomier sleeve has space for a hard-shell case, a few papers or a thin notebook beside the laptop. That is handy, but the extra room also lets the laptop move. If you want space for other things, choose a sleeve with a separate front pocket for them instead, so the laptop compartment can stay snug and the charger is not pressing on the lid. Some sleeves have a deeper pocket that takes a charger and a mouse.
Materials and the fit
Material changes how a sleeve sits as well as how it looks. Felt holds its shape and does not stretch. Leather and leather-look sleeves are firm and soften a little with use. Fabric sleeves with foam padding fall somewhere between. There are ranges of felt and fabric and leather and leather-look accessories if you prefer one material.
Sleeve or bag compartment
The same rules apply to a bag's laptop compartment, with one difference: a bag compartment is often made slightly roomy on purpose, so it takes a range of laptops of that size class and, often, a laptop already in a sleeve. If you plan to use both, check the compartment's measurements are big enough for the laptop in its sleeve. The guide to laptop bags compared explains the different kinds of bag.
Pockets and handles change the fit
A sleeve with a front pocket gets thicker when the pocket is full. A charger and a mouse in the pocket can add a few centimetres, which matters if the sleeve is going into a bag compartment that was a close fit for the laptop alone. Handles and straps add very little to the size but can catch on the opening of a tight compartment. If you plan to keep a sleeve inside a bag, a slim sleeve without bulky pockets is usually the easier fit, and the charger can go in the bag itself or in a tech pouch.
Skins and shells
A stick-on skin adds almost nothing to a laptop's size, so it makes no difference to the sleeve you need. A hard-shell case adds a little all round, more at the corners, so measure with it on.
Thinking about the next laptop
A sleeve chosen to fit one laptop closely may not suit the next, even if it has the same screen size, because shapes and thicknesses change from model to model and maker to maker. If you change laptops, measure the new one rather than assuming the old sleeve will do. A sleeve that is slightly too big can be used inside a bag for a while, but one that is too small will not close at all.
If you are not sure between two sizes
If your laptop falls between two size groups, compare the inside measurements of both. The usual mistake is choosing the smaller size by screen alone and finding the laptop is too deep or too thick, so if one is clearly too tight in any direction, choose the other.
Questions people ask
Is a 13-inch sleeve the same as a 13.3-inch sleeve?
Usually, yes. Most sleeves sold as 13-inch are made for the 13 to 13.3-inch size class. Laptops with taller screens or slightly bigger screens, such as 13.6 inches, may need a little more depth, so check the measurements.
Will my 14-inch laptop fit a 15.6-inch sleeve?
It will go in, but it will move about inside, which lets the corners take knocks. A sleeve that matches the laptop's own size protects it better.
Which sleeve suits a 13-inch MacBook Air?
Apple lists the current 13-inch MacBook Air at 30.41 by 21.5 cm and 1.13 cm thick. Choose a sleeve whose inside measurements are a little bigger than that, and allow for a shell if you use one.
Should I measure with the hard-shell case on?
Yes, if you keep the shell on. A shell adds a little to the width, depth and thickness, and that is often the difference between a sleeve zipping easily and not zipping at all.
What does "fits up to 15.6 inches" mean on a bag?
It means the bag's laptop compartment is made for laptops of that size class or smaller. It does not mean every laptop of that size will fit, so compare your laptop's depth and thickness with the compartment's measurements if they are given.
Why is my 16-inch laptop bigger than my old 15.6-inch one?
Most 16-inch laptops have a taller screen shape (16:10 rather than 16:9), so for about the same width they are deeper from front to back.
Where to go next
Find your size in 13-inch, 14-inch, 15.6-inch, 16-inch or 17-inch sleeves, or browse all laptop sleeves. Delivery is included in every price and tracked to your door. Other guides that help:
- How to choose a laptop sleeve or bag: the whole choice, from sleeve to bag
- Laptop backpacks, messenger bags and briefcases compared: when a sleeve is not enough
- Accessories for MacBook Air and MacBook Pro: shells, sleeves and more
- Privacy and protection: filters, screen protectors, skins and locks: looking after the laptop itself
