40x30x10 cm is the personal item size limit found on several carriers, including Lufthansa and Singapore Airlines.
This is among the most restrictive dimension constraints on any major airline.
As a result, finding bags that work with all three of the dimensions can be a challenge.

Does anyone have any favorites that are within (but as close as possible to) this size limit?
Ideally a light backpack that can fit a 16" Macbook Pro (35.79x24.59x1.62 cm), but anything is welcome. Especially discussion on which bags are the highest quality and most practical.
But if anyone finds the fabled 40x30x10 cm backpack, please let me know!

This is a list of items that have been recommended in the past, so that users interested can find this information in one place:
| <40x30x10 || Type || Linear || H || W || D || Volume (L) || Weight (g) || Price || Brand || Item
|-
| TRUE || Backpack || 77.5 || 39.4 || 28.6 || 9.5 || 11 || 1000 || $229.00 || Waterfield || Sutter Slim Backpack
|-
| TRUE || Briefcase || 72.0 || 36.0 || 26.0 || 10.0 || 8 || 359 || $85.00 || Tom Bihn || Daylight Briefcase
|-
| TRUE || Briefcase || 76.0 || 39.0 || 28.0 || 9.0 || ? || ? || $168.00 || Tokyo Bags || Soma Japanese Briefcase
|-
| TRUE || Briefcase || 77.0 || 40.0 || 30.0 || 7.0 || ? || ? || $185.00 || Tokyo Bags || Abiko Briefcase
|-
| TRUE || Briefcase || 77.5 || 38.1 || 29.8 || 9.5 || 10.8 || 990 || $249.00 || Waterfield || Hitch Crossbody Laptop Brief (Large)
|-
| TRUE || Briefcase || 78.0 || 40.0 || 28.0 || 10.0 || ? || ? || $158.00 || Tokyo Bags || Abiko II Briefcase
|-
| FALSE || Backpack || 73.7 || 35.6 || 26.7 || 11.4 || 10.8 || 130 || $18.00 || Rick Steves || Packable Backpack
|-
| FALSE || Backpack || 77.0 || 38.0 || 27.0 || 12.0 || 16 || 330 || $70.00 || Pacsafe || Daysafe Anti-Theft Backpack
|-
| FALSE || Backpack || 77.5 || 43.2 || 22.9 || 11.4 || 12 || 567 || ? || Recycled Firefighter || The Battalion 12HR
|-
| FALSE || Backpack || 77.8 || 42.2 || 25.4 || 10.2 || 15 || 960 || $240.00 || Triple Aught Design || Fast Pack Scout
|-
| FALSE || Backpack || 77.9 || 40.4 || 25.0 || 12.5 || 13.3 || 900 || $159.00 || Timbuk2 || WMN Never Check Day Backpack
|-
| FALSE || Backpack || 78.0 || 38.0 || 27.0 || 13.0 || 16 || 395 || $90.00 || Fjällräven || Re-Kånken
|-
| FALSE || Backpack || 78.7 || 39.4 || 27.9 || 11.4 || 16 || ? || $110.00 || Sherpani || Soleil AT
|-
| FALSE || Backpack || 79.2 || 39.9 || 27.9 || 11.4 || 14 || 953 || $120.00 || Everki || Studio Slim Backpack 14.1"
|-
| FALSE || Backpack || 79.4 || 43.2 || 29.2 || 7.0 || 16.4 || 953 || $70.00 || Swissgear || 3573 Laptop Backpack
|-
| FALSE || Backpack || 79.5 || 43.0 || 29.0 || 7.5 || ? || 1000 || $289.00 || Briggs & Riley || Kinzie Street ZK265X
|-
| FALSE || Backpack || 80.0 || 41.0 || 28.0 || 11.0 || 18 || ? || $59.95 || Johnny Urban || Roll Top Backpack "Robin"
|-
| FALSE || Backpack || 80.0 || 43.2 || 26.7 || 10.2 || 15 || 400 || $79.00 || Patagonia || Arbor Market Pack 15L
|-
| FALSE || Backpack || 80.0 || 40.6 || 27.9 || 11.4 || 15 || ? || $100.00 || Sherpani || Camden
|-
| FALSE || Backpack || 81.3 || 43.2 || 29.2 || 8.9 || 6 || 900 || $159.00 || Arc'teryx || Blade 6 Backpack
|-
| FALSE || Backpack || 81.5 || 41.0 || 28.0 || 12.5 || 12.5 || 400 || $59.00 || Eagle Creek || Wayfinder Backpack Mini
|-
| FALSE || Backpack || 81.9 || 40.0 || 29.2 || 12.7 || 20 || 520 || $79.00 || Patagonia || Tamangito Pack 20L
|-
| FALSE || Backpack || 82.0 || 42.0 || 28.0 || 12.0 || ? || 90 || $26.95 || Onya || Backpack
|-
| FALSE || Backpack || 82.0 || 42.0 || 29.0 || 11.0 || ? || 435 || $65.00 || Eastpak || Ciera
|-
| FALSE || Backpack || 82.0 || 43.0 || 28.0 || 11.0 || 13 || ? || $59.95 || Johnny Urban || Liam Backpack
|-
| FALSE || Backpack || 82.6 || 40.6 || 27.9 || 14.0 || ? || 700 || $219.00 || Briggs & Riley || Rhapsody PK130
|-
| FALSE || Backpack || 83.0 || 43.0 || 29.0 || 11.0 || 20 || 510 || $100.00 || Pacsafe || Intasafe X Anti-Theft 15" Laptop Slim Backpack
|-
| FALSE || Backpack || 83.0 || 40.0 || 30.0 || 13.0 || ? || 1450 || $395.00 || Boita || Backpack
|-
| FALSE || Backpack || 83.0 || 43.0 || 30.0 || 10.0 || 13 || ? || $79.95 || Johnny Urban || Laptop Backpack "Brandon"
|-
| FALSE || Backpack || 83.2 || 43.2 || 30.5 || 9.5 || 18 || 700 || $149.00 || Patagonia || Stand Up Pack 18L
|-
| FALSE || Backpack || 83.8 || 40.6 || 30.5 || 12.7 || ? || 456 || $100.00 || Alchemy Goods || Fremont Salvaged Charcoal Denim Backpack
|-
| FALSE || Briefcase || 74.9 || 40.6 || 27.9 || 6.4 || ? || ? || $195.00 || Matt & Nat || BELEM Briefcase
|-
| FALSE || Briefcase || 76.2 || 40.6 || 25.4 || 10.2 || 10.5 || 1700 || $285.00 || Red Oxx || C.C. Rider
|-
| FALSE || Briefcase || 77.5 || 39.4 || 27.9 || 10.2 || 11 || 1130 || $269.00 || Waterfield || Bold Briefcase (Medium)
|-
| FALSE || Briefcase || 80.0 || 41.0 || 29.0 || 10.0 || ? || 800 || $195.00 || Corkor || Cork Briefcase
|-
| FALSE || Briefcase || 80.0 || 43.2 || 27.9 || 8.9 || 10.7 || 1430 || $225.00 || Red Oxx || Metro Laptop Briefcase
|-
| FALSE || Briefcase || 81.0 || 39.0 || 29.0 || 13.0 || 13 || 475 || $165.00 || Tom Bihn || Pilot
|-
| FALSE || Briefcase || 82.3 || 42.9 || 30.0 || 9.4 || 15 || 1043 || $110.00 || Everki || Flight Briefcase 16"
|-
| FALSE || Briefcase || 82.6 || 40.6 || 33.7 || 8.3 || ? || ? || $240.00 || Matt & Nat || ELON Briefcase
|-
| FALSE || Briefcase || 82.8 || 41.9 || 32.0 || 8.9 || 18 || 998 || $100.00 || Everki || Contempro Briefcase 15.6"
|-
| FALSE || Briefcase || 83.0 || 40.5 || 29.0 || 13.5 || ? || 1400 || $279.00 || Briggs & Riley || Kinzie Street ZB235
|-
| FALSE || Messenger || 80.0 || 43.0 || 30.0 || 7.0 || ? || 930 || $159.50 || Corkor || Messenger Bag
|-
| FALSE || Messenger || 82.6 || 38.6 || 32.0 || 11.9 || 15.5 || 816 || $100.00 || Everki || Contempro Shoulder Bag 14.1"