40L Travel Backpacks
Forty liters is the one-bag standard for a reason. What it does not tell you is the shape — and three 40L packs here fit between four and eleven US carriers.
We have not tested this gear. Every figure here is compiled from published manufacturer specifications and published airline policies, and the arithmetic is public so you can check it. This page contains affiliate links — see the affiliate disclosure.
Forty liters is the largest capacity that reliably fits a 22 × 14 × 9 in carry-on box — but capacity does not decide compliance, shape does. The three 40 L packs here publish 22 × 14 × 8, 22 × 14 × 9 and 21.7 × 13.8 × 9.1 in, and they clear eleven, eleven and four US carriers respectively.
| # | Product | Published size | Fits | Score | Price |
|---|---|---|---|---|---|
| 1 | Osprey Fairview 40 Travel PackShorter torsos, and anyone the Farpoint's shoulder straps do not suit | 22 × 14 × 9 in | 11 of 11AA DL UA WN … | 8.6 | Check price#ad How we earn |
| 2 | Osprey Farpoint 40 Travel PackOne-bag travel on any carrier that measures | 21.7 × 13.8 × 9.1 in | 4 of 11WN F9 G4 SY | 7.2 | Check price#ad How we earn |
| 3 | Peak Design Travel Backpack 45LFlying carriers with different limits on the outbound and the return | 22 × 13 × 9.5 in | 4 of 11WN F9 G4 SY | 5.9 | Check price#ad How we earn |
| 4 | Tortuga Travel Backpack Pro 40LReaders who want the tightest published depth in a 40 L bag | 22 × 14 × 8 in | 11 of 11AA DL UA WN … | 4.1 | Not sold on Amazon#ad How we earn |
No live price is currently verified, so every button here reads Check price rather than a number we cannot stand behind. See how we handle prices.
Why 40 liters became the standard
It is arithmetic rather than fashion. The standard carry-on box — 22 × 14 × 9 in — is 2,772 in³, which is 45.4 L of geometry. A soft pack loses roughly ten percent of that to seams, padding, harness structure and the fact that a bag is not a perfect prism. 40 L is what is left.
That is why 40 L appears again and again across brands that otherwise have nothing in common: it is the honest answer to “the biggest pack that is still a carry-on”. The full conversion is worked here.
Same liters, different shape
Three packs, all 40 L published, all built to be carry-ons. Their published boxes are meaningfully different and so are their fit results.
| Pack | Published size | Depth | Box volume | US carriers |
|---|---|---|---|---|
| Tortuga Travel Backpack Pro 40L | 22 × 14 × 8 in | 8 in | 40.4 L | 11 of 11 |
| Osprey Fairview 40 | 22 × 14 × 9 in | 9 in | 45.4 L | 11 of 11 |
| Osprey Farpoint 40 | 21.7 × 13.8 × 9.1 in | 9.1 in | 44.6 L | 4 of 11 |
The Tortuga row is the interesting one. Its box volume is 40.4 L and its published capacity is 40 L — a loss of one percent, which is remarkable for a structured bag and tells you the design is built around the box rather than around a capacity target. The Fairview achieves the same 40 L inside a 45.4 L box, losing twelve percent to structure.
Neither is wrong. The Tortuga is more space-efficient and an inch shallower; the Fairview has more room for its harness and adjustment. But if fitting a sizer is your priority, the pack that wastes least of its box is the one that gives you the most margin.
What 40 liters actually holds
A week, packed deliberately, for most people. The honest reference points:
- Five to seven changes of clothes, in cubes or rolled
- One extra pair of shoes — two if one pair is worn
- A 15 or 16 inch laptop in a dedicated sleeve
- A quart bag of liquids plus a toiletry kit
- A light jacket, or a packable shell that goes in a corner
What does not fit is bulk. A winter coat, hiking boots or camera gear will eat a third of the pack on their own, and that is where the argument for 45 L comes in — with the caveat that 45 L is over the standard box on every carrier that publishes 22 × 14 × 9 in.
The week-in-a-carry-on method is the page that makes 40 L work in practice, and the one-bag packing list is what goes in it.
35, 40 or 45?
| Capacity | Suits | Carry-on compliant? | In our ledger |
|---|---|---|---|
| 35 L | Three to five days, or a week with laundry | Almost always — comfortably inside the box | Cotopaxi Allpa 35L at 2.93 lb |
| 40 L | A week, packed deliberately | Depends entirely on shape | Farpoint 40, Fairview 40, Tortuga Pro 40L |
| 45 L | A week with bulk — coat, boots, camera | Over the standard box on depth | Peak Design Travel Backpack 45L |
The Peak Design deserves its caveat and its credit in the same breath: it compresses from 45 L down to 35 L, which is the only genuine answer to a carry-on limit that changes between the outbound and the return. If you fly one carrier out and a stricter one home, that mechanism is worth more than any single fixed capacity.
The recommendation
- Best all-round 40 L → Osprey Farpoint 40. The best carry efficiency on this site at 0.08 lb per liter, an open-ended warranty, and $9.25 per covered year. Its tenth-of-an-inch depth overage is arithmetic rather than a practical problem on a compressible pack.
- Best 40 L that certainly fits → Tortuga Travel Backpack Pro. 8 in of published depth is a full inch of margin. Sold direct, and we earn nothing on it.
- Shorter torso → Osprey Fairview 40, which fits every carrier and every published limit at exactly 22 × 14 × 9 in. The two Ospreys compared.
- Variable limits between legs → Peak Design, for the compression mechanism rather than the capacity.
Every pick, with the working
Each entry below shows the published inputs, the four axis scores they produce, and what you give up. The order is the computed order, not a commercial one.
1 · Shorter torsos, and anyone the Farpoint's shoulder straps do not suit
Osprey Fairview 40 Travel Pack
The Farpoint's harness geometry rebuilt for a shorter torso and narrower shoulders, at exactly the published 22 × 14 × 9 in box.
- Published size
- 22 × 14 × 9 in
- Weight
- 3.44 lb
- Capacity
- 40 L
- Weight per liter
- 0.09 lb/L
- Cost per covered year
- $10/yr
- Published list price
- $200
Warranty All Mighty Guarantee — limited lifetime
Fits 11 of 11 US carriers: AA, DL, UA, WN, AS, B6, F9, G4, HA, MX, SY. See the limits.
What it does well
- Published dimensions match the standard carry-on box exactly
- Adjustable torso length rather than a fixed harness
- Same All Mighty Guarantee as the Farpoint
What you give up
- $200 against the Farpoint's $185 for 0.17 lb more weight
- At exactly 22 × 14 × 9 in there is no margin for a stuffed pack
- Laptop sleeve takes 16 in, so a larger machine travels elsewhere
The arithmetic behind the score
- Value 6.8/10 — $200 ÷ 20 yr = $10/yr; $200 ÷ 40 L = $5/L
- Airline-fit breadth 10.0/10 — Fits the published carry-on limit at 11 of 11 US carriers: AA, DL, UA, WN, AS, B6, F9, G4, HA, MX, SY
- Carry efficiency 8.6/10 — 3.44 lb ÷ 40 L = 0.086 lb/L
- Warranty & support 10.0/10 — no stated end date (6 of 6); repair published (+2); covers airline damage (+2)
Weights and breakpoints are published on how we rank. Where an input is not published, that axis is dropped and the remaining weights are re-normalized.
Specs: Osprey published specifications and price, compiled 3 September 2026.
2 · One-bag travel on any carrier that measures
Osprey Farpoint 40 Travel Pack
40 L that fits the standard 22 × 14 × 9 in box on height and depth, weighs 3.27 lb, and carries a warranty with no stated end date. It is the strongest single row in this ledger.
- Published size
- 21.7 × 13.8 × 9.1 in
- Weight
- 3.27 lb
- Capacity
- 40 L
- Weight per liter
- 0.08 lb/L
- Cost per covered year
- $9.25/yr
- Published list price
- $185
Warranty All Mighty Guarantee — any reason, any product, any era
Fits 4 of 11 US carriers: WN, F9, G4, SY. See the limits.
What it does well
- 0.08 lb per liter is the best carry efficiency figure on this site
- The All Mighty Guarantee names no failure cause and no time limit
- 21.7 in height clears the 22 in standard with room to spare
What you give up
- 13.8 in width clears 14 in only when the pack is not overstuffed — soft bags grow
- No wheels, so a long terminal is carried on your back
- $9.25 per covered year is good but not the cheapest here
The arithmetic behind the score
- Value 7.2/10 — $185 ÷ 20 yr = $9.25/yr; $185 ÷ 40 L = $4.63/L
- Airline-fit breadth 3.6/10 — Fits the published carry-on limit at 4 of 11 US carriers: WN, F9, G4, SY
- Carry efficiency 8.7/10 — 3.27 lb ÷ 40 L = 0.082 lb/L
- Warranty & support 10.0/10 — no stated end date (6 of 6); repair published (+2); covers airline damage (+2)
Weights and breakpoints are published on how we rank. Where an input is not published, that axis is dropped and the remaining weights are re-normalized.
Specs: Osprey published specifications and price, compiled 3 September 2026.
3 · Flying carriers with different limits on the outbound and the return
Peak Design Travel Backpack 45L
Skip this one. It is not a 40 L pack and it is on this page as the alternative rather than the pick. At 45 L expanded it is over the standard box on depth, and at 4.52 lb it is a pound and a quarter heavier than the Farpoint for five more liters. If a fixed 40 is what you want, buy a fixed 40.
A 45 L bag that compresses to 35 L is the honest answer to a carry-on limit that changes by carrier — you shrink the bag rather than repack it.
- Published size
- 22 × 13 × 9.5 in
- Weight
- 4.52 lb
- Capacity
- 45 L
- Weight per liter
- 0.10 lb/L
- Cost per covered year
- $15/yr
- Published list price
- $300
Warranty Peak Design lifetime product warranty
Fits 4 of 11 US carriers: WN, F9, G4, SY. See the limits.
What it does well
- Compresses from 45 L to 35 L, which is the only real answer to a variable limit
- Lifetime warranty at $15 per covered year
- Two laptop and tablet compartments as published, not an afterthought sleeve
What you give up
- 4.52 lb is 1.25 lb heavier than the Farpoint for 5 L more capacity
- $300 published price is the second-highest in this ledger
- Expanded to 45 L it is over the standard box on depth at every US carrier
The arithmetic behind the score
- Value 5.0/10 — $300 ÷ 20 yr = $15/yr; $300 ÷ 45 L = $6.67/L
- Airline-fit breadth 3.6/10 — Fits the published carry-on limit at 4 of 11 US carriers: WN, F9, G4, SY
- Carry efficiency 8.0/10 — 4.52 lb ÷ 45 L = 0.100 lb/L
- Warranty & support 8.0/10 — no stated end date (6 of 6); repair published (+2); airline damage not covered (+0)
Weights and breakpoints are published on how we rank. Where an input is not published, that axis is dropped and the remaining weights are re-normalized.
Specs: Peak Design published specifications and price, compiled 3 September 2026. Peak Design publishes an expandable range: roughly 22 × 13 × 9 in compressed to 35 L, and 22 × 13 × 11 in expanded to 45 L. The 9.5 in figure here is the published exterior depth at the standard setting.
4 · Readers who want the tightest published depth in a 40 L bag
Tortuga Travel Backpack Pro 40L
The only 40 L pack in this ledger published at 8 in deep, which is the dimension that actually decides whether a soft bag passes a sizer.
- Published size
- 22 × 14 × 8 in
- Weight
- 4.4 lb
- Capacity
- 40 L
- Weight per liter
- 0.11 lb/L
- Cost per covered year
- Not published
- Published list price
- $350
Warranty Tortuga Worldwide Warranty — no published term
Fits 11 of 11 US carriers: AA, DL, UA, WN, AS, B6, F9, G4, HA, MX, SY. See the limits.
What it does well
- 8 in published depth is an inch inside the 9 in standard, which is where soft bags usually fail
- 22 × 14 × 8 in clears the standard box on all three dimensions as published
- Weatherproof recycled ECOPAK shell with lockable zippers
What you give up
- Sold direct rather than on Amazon, and we have joined no Tortuga program — we earn nothing if you buy it
- $350 with no published warranty term
- 4.4 lb is a pound and a bit more than the Farpoint for the same 40 L
The arithmetic behind the score
- Value 0.3/10 — $350 ÷ 40 L = $8.75/L
- Airline-fit breadth 10.0/10 — Fits the published carry-on limit at 11 of 11 US carriers: AA, DL, UA, WN, AS, B6, F9, G4, HA, MX, SY
- Carry efficiency 7.6/10 — 4.4 lb ÷ 40 L = 0.110 lb/L
- Warranty & support 0.0/10 — no published term (0 of 6); no published repair route (+0); airline damage not covered (+0)
Weights and breakpoints are published on how we rank. Where an input is not published, that axis is dropped and the remaining weights are re-normalized.
Tortuga sells this direct. We have joined no Tortuga program, so we earn nothing if you buy it — which is exactly why it is still here.
Specs: Tortuga published specifications and price, compiled 3 September 2026.
No live price is currently verified, so every button here reads Check price rather than a number we cannot stand behind. See how we handle prices.