A laptop bag has one job before any other: the laptop has to fit inside it. The screen size on the label is a poor guide to that, so this guide starts with the laptop maker's own measurements. It then compares sleeves, backpacks, briefcases and hard-shell cases, sets out what the bag makers actually say about padding and rain, and lists the under-seat limits British Airways, easyJet and Ryanair publish. Five bags from tomtoc, Targus, Case Logic and Amazon Basics follow, each with its size limit.
Take the laptop's width, depth and thickness from its maker's spec page, then choose a bag whose internal compartment is at least that big: tomtoc's 13-inch sleeve lists the same inside width and depth as Apple's 13-inch MacBook Air. Pick a sleeve to go inside another bag, a backpack for commuting or a slim briefcase, and check the airline's under-seat limit, 40 x 30 x 15 cm on British Airways, before flying.
Key Takeaways
- Apple's tech specs put the 13-inch MacBook Air at 30.41 x 21.5 x 1.13 cm, and tomtoc's 13-inch sleeve lists an inside size that matches that width and depth.
- Bag makers publish compartment sizes: Targus gives 38.7 x 26.5 x 2.5 cm for the Drifter, room on paper for Apple's 16-inch MacBook Pro at 35.57 x 24.81 cm.
- British Airways allows a 40 x 30 x 15 cm under-seat bag, easyJet 45 x 36 x 20 cm and Ryanair 40 x 30 x 20 cm, smaller than many laptop backpacks.
- BA says laptops belong in hand baggage and power banks in the smaller under-seat bag, and the CAA limits each passenger to two power banks in carry-on bags.
- Padding and rain claims are the makers' own: tomtoc gives no drop height for its CornerArmor sleeve, and none of the five bags here is sold as waterproof.
Measure the Laptop, Not the Screen Size
Screen size is a diagonal, and a bag has to take the whole machine. Apple's MacBook Air tech specs say screen size is measured diagonally, and that the 13-inch model's display measures 13.6 inches as a standard rectangle. The same page lists the 13-inch MacBook Air at 30.41 cm wide, 21.5 cm deep and 1.13 cm thick, and the 15-inch model at 34.04 by 23.76 by 1.15 cm.
Some bag makers publish the matching figures. tomtoc's page for its 13-inch 360 protective sleeve gives an internal size of 11.97 by 8.46 by 0.61 inches, which works out at 30.4 by 21.5 by 1.55 cm, a snug match for Apple's width and depth. Targus lists the Drifter backpack's laptop compartment at 38.7 by 2.5 by 26.5 cm, room on paper for Apple's 16-inch MacBook Pro at 35.57 by 24.81 by 1.68 cm.
Labels can mislead. Amazon's listing for its 15.6-inch Amazon Basics sleeve says it fits the 16-inch MacBook Pro, and tells buyers to check that the device dimensions match the internal space.
Sleeves, Backpacks and Briefcases Carry in Different Ways
A sleeve is the slimmest option, a padded jacket for the laptop alone. Amazon's listing for its 15.6-inch Amazon Basics sleeve says it can be used alone or slipped into a bag, and tomtoc adds a 9.45 by 7.68 inch front pocket to its 13-inch sleeve for a charger or cables.
A backpack spreads the weight over two straps. Targus gives its Drifter a 32-litre capacity and heavily padded shoulder straps. Briefcases and messenger bags keep a slimmer shape on one strap. Targus's UK page puts its 17.3-inch GeoLite EcoSmart Slim Brief at 5.7 cm thick, and both it and Case Logic's Advantage attaché have a strap that fixes the bag to a wheeled suitcase.
A hard-shell case is a cover rather than a carrier. It clips on to the laptop itself, so it still needs a sleeve or bag for the journey. If a shell comes with a keyboard cover, Apple's support article on covers says to remove it before closing the display, because the gap between screen and keyboard deck is engineered to tight tolerances.
Padding and Corner Protection Are the Makers' Claims
Every laptop bag is sold as protective, and the wording comes from the makers rather than from any published test. tomtoc's sleeve page leads on what it calls military-grade CornerArmor protection, with high-resilience edges and soft padding that it says absorb impacts and shocks to keep the laptop safe from drops. The page gives no drop height.
The others describe their padding more plainly. Targus promises superior internal padding in the Drifter, and a zippered, padded laptop compartment with a document divider in the Slim Brief. Case Logic describes padded storage for a laptop up to 14 inches in the Advantage, while Amazon's listing gives its Amazon Basics shoulder bag a padded polyester lining.
With no figures to compare, the useful checks are the ones a buyer can see on the spec page. A separate padded compartment keeps the laptop away from keys and charger plugs. A compartment sized close to the laptop's own measurements stops it sliding about. For a laptop carried every day, a sleeve inside a backpack gives it two layers of padding.
Water-Resistant Is the Makers' Word, Not Waterproof
Rain is the other worry on a British commute, and here too the claims belong to the makers. tomtoc describes its sleeve as made from spill-resistant recycled fabrics with water-repellent treatments, without added PFAS. Targus calls the Slim Brief's fabric water-resistant, while its page for the Drifter describes a water-resistant base. Amazon's listing gives the Amazon Basics shoulder bag a polyester exterior with a water-repellent finish. Case Logic's page for the Advantage does not mention water resistance at all.
None of the five is sold as waterproof, and none of these pages says how much rain the fabric will take or for how long. That leaves two practical choices for anyone who walks or cycles to work in all weathers.
The first is layers: a sleeve inside a water-resistant backpack puts two coverings between the laptop and the weather. The second is to keep the charger and any cables in a zipped pocket of their own, so a wet umbrella or bottle never shares space with the laptop.
Airline Under-Seat Limits Are Smaller Than Most Laptop Bags
Flying is where size stops being a matter of taste. British Airways' baggage page allows one hand bag of up to 40 x 30 x 15 cm, which must fit under the seat in front, plus a cabin bag of up to 56 x 45 x 25 cm including wheels and handles. easyJet lets every passenger bring one small under-seat bag of up to 45 x 36 x 20 cm, including handles and wheels, and names a laptop bag as an example. Ryanair's bag policy includes one small personal bag of 40 x 30 x 20 cm, such as a handbag or laptop bag, on every fare.
On paper, plenty of laptop bags are too big for the free allowance. Targus lists the Drifter at 37 x 20 x 48 cm, over all three under-seat limits. Case Logic's Advantage, at 37 x 7 x 33 cm, fits easyJet's size, but its 33 cm side is over the 30 cm BA and Ryanair allow. tomtoc's 13-inch sleeve, at 13.39 by 9.65 by 1.57 inches outside, fits within all three.
Laptops, Chargers and Power Banks Stay in the Cabin
British Airways says small electronic devices such as laptops and tablets should be carried in hand baggage, and that its larger cabin bag should hold no valuables or electronics because it may need to go in the hold. BA also wants spare batteries and power banks in the smaller under-seat bag. So the small bag is the place for the laptop and its kit.
GOV.UK's hand luggage rules allow laptops in both hand and hold luggage, and ask travellers to charge their devices before travelling, because a device that does not switch on when requested will not be allowed onto the aircraft. BA adds that security staff may ask you to turn devices on.
The Civil Aviation Authority's rules allow no more than two power banks per person, in carry-on baggage only, and none may be recharged on board. The power bank guide covers the watt-hour limits, and the replacement laptop charger guide explains how to read a charger's wattage. A USB-C hub and a folding laptop stand also deserve a pocket for work away from a desk.
Five Bags From Known Brands, Each With a Size Limit
Each pick has a limit worth checking against the laptop first. tomtoc's 360 protective sleeve is cut for the 13-inch MacBook Air, with an inside size that matches Apple's width and depth, and suits anyone who already owns a bag. Targus's Drifter is the commuter backpack, though Targus's own page lists it for 15.6-inch laptops in its specifications and up to 16 inches in its overview, so check the 38.7 by 26.5 cm compartment against the laptop.
For a big laptop, Targus's GeoLite EcoSmart Slim Brief takes 17.3 inches and under, at 43.5 x 5.7 x 31 cm and 0.76 kg by Targus's UK page. Case Logic's Advantage attaché suits laptops up to 14 inches, with a slip pocket for a 10.1-inch tablet, and weighs 0.39 kg by Case Logic's figures. Amazon Basics' slim shoulder bag is the budget choice for laptops up to 15.6 inches, with zipped pockets that Amazon's listing says suit cables and a power bank.
On paper, only the sleeve fits inside BA's 40 x 30 x 15 cm under-seat limit.
| Product | Best for | Key specs | Price | |
|---|---|---|---|---|
 | tomtoc 360 Protective Laptop Sleeve for 13-inch MacBook Air Sleeve | A 13-inch MacBook Air carried inside another bag | Inside 11.97 x 8.46 x 0.61 in, CornerArmor, front pocket | Check price → |
 | Targus Drifter Laptop Backpack (TSB238EU) Backpack | Commuting with a 15.6 to 16 inch laptop | Compartment 38.7 x 26.5 x 2.5 cm, 32 litres, 1.28 kg | Check price → |
 | Targus 17.3-inch GeoLite EcoSmart Slim Brief (TSS991GL) Briefcase | Laptops up to 17.3 inches in a slim shoulder case | 43.5 x 5.7 x 31 cm, 0.76 kg, water-resistant fabric | Check price → |
 | Case Logic Advantage 14-inch Laptop Attaché (3203986) 14-inch pick | Laptops up to 14 inches plus a 10.1-inch tablet | Compartment 37 x 7 x 29 cm, 0.39 kg, luggage strap | Check price → |
 | Amazon Basics Slim Laptop Shoulder Bag, 15.6 inch Budget | Laptops up to 15.6 inches on a tight budget | 42 x 33 x 8.5 cm outside, 449 g, water-repellent finish | Check price → |