Laptop Bag Sizes: Size Chart and How to Measure
Laptop bags are labeled by screen size, but what has to fit is the laptop's body. This chart gives the inside compartment size each laptop size needs, how to measure, and the airline and security rules that apply to laptop bags.
A laptop bag is labeled with the largest screen size it is designed for, such as 14, 15.6 or 17.3 inches. To be sure of a fit, the laptop compartment's inside size should be about 1 cm (0.4 in) larger than the laptop body in width and depth: about 33.5 × 23.5 cm (13.2 × 9.3 in) for a 14-inch laptop, 37 × 25 cm (14.6 × 9.8 in) for 15.6 inches and 41 × 27 cm (16.1 × 10.6 in) for 17.3 inches.
- 13-inch laptop
- 31.5 × 22.5 cm inside
- 14-inch laptop
- 33.5 × 23.5 cm inside
- 15.6-inch laptop
- 37 × 25 cm inside
- 17.3-inch laptop
- 41 × 27 cm inside
On this page
Laptop bag size chart
The middle column is the largest laptop body of that size among current and recent models, from manufacturer spec sheets. The right-hand columns are the inside compartment size that body needs, with about 1 cm (0.4 in) of clearance in each direction. Padding compresses a little, but a compartment smaller than the laptop is a struggle every time you pack.
| Bag label / laptop size | Largest laptop bodies (cm) | Compartment needed (in) | Compartment needed (cm) |
|---|---|---|---|
| 11.6–12.5 in | up to 31.0 × 21.9 | 12.6 × 9.1 | 32 × 23 |
| 13–13.6 in | up to 30.4 × 21.5 | 12.4 × 8.9 | 31.5 × 22.5 |
| 14 in | up to 32.4 × 22.4 | 13.2 × 9.3 | 33.5 × 23.5 |
| 15–15.3 in (MacBook Air 15) | up to 34.0 × 23.8 | 13.8 × 9.8 | 35 × 25 |
| 15.6 in | up to 36.0 × 23.6 (25.1 gaming) | 14.6 × 9.7 (10.3 gaming) | 37 × 24.6 (26.1 gaming) |
| 16 in | up to 36.4 × 26.8 | 14.6–14.8 × 10.2–11.0 | 37–37.5 × 26–28 |
| 17–17.3 in | up to 40.1 × 29.3 | 16.1 × 10.6–12.0 | 41 × 27–30.5 |
| 18 in | about 39.9 × 29.8 | 16.1 × 12.2 | 41 × 31 |
Thickness rarely limits the fit of the laptop itself, since laptops are 1.1 to 3.2 cm thick. It does matter for slim sleeves and for compartments that also take a charger: allow about 3 cm (1.2 in) of compartment thickness for a thin laptop and 4 cm (1.6 in) for a gaming laptop. Model-by-model laptop dimensions are on the laptop sizes page.
A 15.6-inch label tells you the bag was designed around 15.6-inch laptops, which are 35.4 to 36 cm wide. A 16-inch laptop has a similar width but can be up to 3 cm deeper, and a 17.3-inch laptop is 4 cm wider. Always compare the bag's listed interior size with your laptop's spec-sheet dimensions.
How to measure your laptop for a bag
- Get the body dimensions. Look up your exact model's width, depth and thickness on the manufacturer's spec page. The model is on the label underneath, in System Information on Windows, or under About This Mac.
- Or measure the closed laptop. Measure width (left to right) and depth (front to back, including the hinge) at the widest points, plus thickness at the thickest point, usually the rear.
- Add clearance. Add about 1 cm (0.4 in) to width and depth for a padded compartment. For a stretchy neoprene sleeve, 0.5 cm is enough; for a hard case, use the case maker's model list instead.
- Include any case. If the laptop lives in a snap-on shell or a school-issued bumper case, measure it with the case on.
- Compare with the bag's interior. Good bag makers list the laptop compartment's inside dimensions separately from the outside size. If only the outside size is given, expect the compartment to be several centimeters smaller each way.
Laptop bag types and how they are sized
| Type | How it is sized | What to check |
|---|---|---|
| Sleeve | By laptop size; often by specific model | Interior within 0.5 to 1.5 cm of the laptop; room for thickness if the zip runs around the edge |
| Briefcase / attaché | By laptop size | Separate padded compartment; room for A4 or Letter documents |
| Messenger bag | By laptop size | Compartment depth; flap length when the bag is full |
| Backpack | By laptop size and volume in liters | Raised laptop sleeve (so the laptop doesn't hit the ground); overall height against airline limits |
| Rolling laptop bag | By laptop size and outer dimensions | Outer size against carry-on limits; handle housing reduces inside depth |
For backpacks, the laptop label tells you about one compartment, while the liter rating tells you about everything else. Our backpack size guide converts liters into what fits, and the messenger bag and briefcase guides cover those styles in more depth.
Laptop bag for a laptop and files
A briefcase that holds a laptop and paperwork needs a document section large enough for the paper, not just the laptop. US Letter is 21.6 × 27.9 cm (8.5 × 11 in) and A4 is 21 × 29.7 cm (8.27 × 11.69 in), and a letter-size file folder is about 24 × 30 cm (9.5 × 11.75 in).
- With a 13 or 14-inch laptop: the paper, not the laptop, can set the bag size. A document section for letter-size folders needs about 25 × 31 cm (9.8 × 12.2 in) inside, slightly more than a 13-inch laptop compartment.
- With a 15.6 or 16-inch laptop: the laptop compartment sets the bag's size, and folders fit easily in a matching document section.
- Gusset: each centimeter of document section holds roughly 100 sheets of standard copy paper (80 gsm paper is about 0.1 mm thick), so a 3 cm (1.2 in) gusset takes about 300 sheets in folders.
See the A4 paper size guide for A4 and Letter dimensions.
Laptop bags on planes: size limits and security
On most airlines a laptop bag or laptop backpack is your personal item, the small bag that goes under the seat in front of you. The limits vary a lot. Figures below are as published in 2026; airlines change them, so check before you fly.
| Airline | Limit (in) | Limit (cm) | Largest laptop that fits, in a slim bag |
|---|---|---|---|
| United Airlines | 17 × 10 × 9 | 43 × 25 × 22 | 14-inch; a 15.6-inch laptop is already 9.3 in deep, so almost any bag around it exceeds the 10 in side |
| Southwest | 16.25 × 13.5 × 8 | 41 × 34 × 20 | 16-inch; 17.3-inch is too tight |
| JetBlue | 17 × 13 × 8 | 43 × 33 × 20 | 17.3-inch in a slim bag |
| Frontier | 18 × 14 × 8 | 46 × 36 × 20 | 17.3-inch |
| Ryanair (free bag) | 15.7 × 11.8 × 7.9 | 40 × 30 × 20 | 15.6 or 16-inch; a 17.3-inch laptop alone is 39.4–40.1 cm wide |
| easyJet (free bag) | 17.7 × 14.2 × 7.9 | 45 × 36 × 20 | 17.3-inch |
The last column assumes a slim bag that adds about 2 to 3 cm to the laptop's width and depth. A full laptop backpack is usually much taller than the laptop, so measure the bag itself, packed. Full carry-on limits are in the carry-on bag size guide and the carry-on rules page.
Security screening and batteries
- US TSA standard lanes: laptops come out of the bag unless it is checkpoint-friendly. That means a laptop-only section that unfolds to lie flat on the belt, with no pockets, metal zips or snaps over or under the laptop, and nothing else packed in that section. Officers can still ask you to take the laptop out.
- TSA PreCheck and CT-scanner lanes: the laptop can usually stay in any bag.
- Batteries: under FAA rules, spare lithium batteries and power banks must go in the cabin, never in checked bags. Laptops themselves should also travel in the cabin; if one must be checked, it has to be fully powered off (not asleep) and protected from damage. Spare batteries of 101 to 160 Wh need airline approval, and larger ones are not allowed.
Keep the charger and power bank out of the laptop section. At a standard lane, a checkpoint-friendly section only works if the laptop is the only thing in it, and loose cables on top of the laptop are a common reason for a bag check.
Frequently asked questions
Can a 14-inch laptop go in a 15.6-inch bag?
Yes. A 15.6-inch compartment is about 4 cm wider and 2 to 3 cm deeper than a 14-inch laptop, so it fits with room to spare. Use the bag's strap or an inner sleeve to stop the laptop sliding and hitting the bottom of the bag when you set it down.
What size bag do I need for a 16-inch laptop?
A bag labeled 16 inches, or a 15.6 to 17-inch bag whose compartment is at least about 37 × 26 cm (14.6 × 10.2 in) inside. Gaming 16-inch models up to 26.8 cm deep need about 28 cm (11 in) of compartment depth.
What is a 15.6-inch laptop bag size in cm?
The laptop compartment should be at least about 37 × 25 cm inside (14.6 × 9.8 in), or 37 × 26 cm for a deeper gaming laptop. The outside of a backpack or briefcase is larger, typically by several centimeters each way, depending on padding and pockets.
Does a laptop bag count as a personal item on a plane?
Yes, on most airlines a laptop bag or backpack counts as your personal item if it fits under the seat and within the airline's size limit, for example 17 × 10 × 9 in on United or 40 × 30 × 20 cm on Ryanair. A laptop bag carried in addition to a full-size carry-on and a personal item is usually not allowed.
Do I have to take my laptop out of the bag at airport security?
At standard US TSA lanes, yes, unless the bag is checkpoint-friendly (a laptop-only section that lies flat with nothing else in it). You can leave it in the bag in TSA PreCheck lanes and in lanes with CT scanners. Rules differ at airports outside the US, so follow the instructions at the checkpoint.
What size laptop bag for a MacBook Air?
The 13-inch MacBook Air (30.4 × 21.5 cm) needs a compartment of about 31.5 × 22.5 cm; the 15-inch MacBook Air (34 × 23.8 cm) about 35 × 25 cm. A 15-inch MacBook Air fits most 15.6-inch compartments; it is 2 cm narrower than a typical 15.6-inch Windows laptop.