Linear Inches, Explained
Add the three dimensions together and you get one number. It is the rule that governs every checked bag in the world, and almost nobody does the arithmetic.
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.
Linear inches = height + width + depth, added together into a single number. Two caps use it: 62 in for checked baggage at almost every carrier, and 45 in for Delta’s cabin bag. A bag can pass every individual dimension and still fail the sum.
| # | Product | Published box | Fits | Score | Price |
|---|---|---|---|---|---|
| 1 | 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 on Amazon#ad How we earn |
| 2 | LEVEL8 Road Runner Carry-On (20 in)Anyone who wants a front laptop pocket on a hard shell | 21.5 × 14.4 × 9.2 in | 4 of 11WN F9 G4 SY | 4.7 | Check price on Amazon#ad How we earn |
| 3 | Travelpro Maxlite 5 Large Check-In Expandable Spinner (29 in)Checked travel where weight allowance is tighter than size allowance | 31 × 21 × 13 in | 0 carriers | 4.4 | Check price on Amazon#ad How we earn |
| 4 | Amazon Basics Hardside Spinner (21 in)One or two trips a year on Southwest, Frontier or Allegiant | 21.6 × 14.9 × 10 in | 4 of 11WN F9 G4 SY | 3.4 | Check price on Amazon#ad How we earn |
| 5 | Samsonite Winfield 3 DLX Large Spinner (28 in)Checked bags carrying anything that would not survive being stacked | 30.5 × 20.5 × 13.25 in | 0 carriers | 2.7 | Check price on Amazon#ad How we earn |
No live price is currently verified, so every button here reads Check price on Amazon rather than a number we cannot stand behind. See how we handle prices.
The arithmetic
There is nothing clever about it, which is why it catches people — nobody expects to be doing addition at a check-in desk.
Use the manufacturer’s overall figure, not its packing size. Makers frequently publish both, retail listings quote the smaller, and the airline measures the larger — wheels, handle housing and all. How a sizer actually measures.
The two caps that use it
| Cap | Applies to | Published by |
|---|---|---|
| 62 linear inches | Checked baggage | Almost every carrier worldwide |
| 45 linear inches | Cabin bag | Delta, in addition to its 22 × 14 × 9 in box |
The 62 in checked cap is close to universal and it is the one that costs money — oversize fees are charged per bag and per leg. The 45 in cabin cap is Delta-specific among the carriers we track. Delta’s two independent tests.
Why the sum exists at all
Three dimensions checked separately can each be marginally over at once. A bag one inch over on every side is a noticeably larger object than the box describes — and under a three-test rule each individual overage might be waved through.
Summing closes that gap with a single number. A bin and a cargo hold are fixed volumes; the linear rule is a crude but effective proxy for volume that a person can check with a tape measure in five seconds.
It is a proxy rather than a measure, which is why the two tests coexist. A very long, very thin bag can sum to under 62 in and still not fit through a hold door — so carriers keep the individual limits as well.
Which bags fail on the sum
The interesting cases are the ones that pass every side and fail the total, because those are the bags people are most confident about.
| Bag | Published overall | Linear inches | Verdict |
|---|---|---|---|
| Osprey Farpoint 40 | 21.7 × 13.8 × 9.1 in | 44.6 in | Passes Delta's 45 in cap with 0.4 in spare |
| LEVEL8 Road Runner 20 in | 21.5 × 14.4 × 9.2 in | 45.1 in | Under the standard height, over Delta's sum |
| Amazon Basics Hardside 21 in | 21.6 × 14.9 × 10 in | 46.5 in | Over on both tests |
| Travelpro Maxlite 5 29 in | 31 × 21 × 13 in | 65 in | Over the 62 in checked cap by 3 |
| Samsonite Winfield 3 DLX 28 in | 30.5 × 20.5 × 13.25 in | 64.25 in | Over the checked cap by 2.25 |
Note the last two rows. Both large checked cases in our ledger exceed the 62-inch cap as published, once wheels and handle housing are counted. That is a category-wide pattern rather than a fault of either bag — 28 and 29 inch cases are sold as checked luggage and most of them publish a total above the limit. The checked-bag arithmetic in full.
How reliably is it enforced
Unevenly, and the pattern is worth knowing.
- Checked bags are weighed every time and measured rarely. The scale is part of the tagging transaction; the tape measure is a decision someone makes.
- Cabin bags are measured when a flight is full and the sizer comes out, which is when the marginal bag is caught.
- Oversize fees are charged per bag, per leg. A connecting round trip can be four charges rather than one, which is why a two-inch overage is worth more attention than it seems.
So a bag at 64 in travels most days. “Most days” is a risk with a published price, and the safe answer is a 27 in case or smaller if you want certainty.
Do the arithmetic once, at home
- Measure the real bag, at its widest points, with wheels and handle included — not the figure on the box.
- Add the three numbers. Write the total on a note in your phone.
- Check it against 62 for anything you check, and against 45 if you fly Delta.
- Do it again with the expansion open, if the bag expands. An expanded case is a different object and it is the one you will fly home with. Why expansion is a return-leg mode.
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 · 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.
2 · Anyone who wants a front laptop pocket on a hard shell
LEVEL8 Road Runner Carry-On (20 in)
The only hard case here with a published height under 22 in, and it pays for that with the worst weight-per-liter figure in the ledger.
- Published size
- 21.5 × 14.4 × 9.2 in
- Weight
- 9.3 lb
- Capacity
- 35 L
- Weight per liter
- 0.27 lb/L
- Cost per covered year
- $9.50/yr
- Published list price
- $189.99
Warranty Lifetime warranty
Fits 4 of 11 US carriers: WN, F9, G4, SY. See the limits.
What it does well
- 21.5 in published height is genuinely under the 22 in standard
- Front-opening laptop pocket that takes a 15.6 in machine
- $9.50 per covered year against a lifetime warranty
What you give up
- 9.3 lb for 35 L is 0.27 lb per liter, more than double the Maxlite 5
- 14.4 in width is still a fifth of an inch over the 14 in standard
- The lightest thing in the bag will be the bag's own dead weight allowance
The arithmetic behind the score
- Value 6.6/10 — $189.99 ÷ 20 yr = $9.50/yr; $189.99 ÷ 35 L = $5.43/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 1.4/10 — 9.3 lb ÷ 35 L = 0.266 lb/L
- Warranty & support 6.0/10 — no stated end date (6 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.
Specs: LEVEL8 published specifications and price, compiled 3 September 2026.
3 · Checked travel where weight allowance is tighter than size allowance
Travelpro Maxlite 5 Large Check-In Expandable Spinner (29 in)
8 lb for a 29 in case is genuinely light, but the published overall size is 65 linear inches — three over the 62 in cap almost every US carrier applies to checked bags.
- Published size
- 31 × 21 × 13 in
- Weight
- 8 lb
- Capacity
- Not published
- Weight per liter
- Not published
- Cost per covered year
- Not published
- Published list price
- Not published
Warranty Built For A Lifetime limited warranty with the Trusted Companion Promise, which Travelpro publishes as covering airline-caused damage for the first year
Fits No US carrier in our table publishes a limit these dimensions satisfy. See the limits.
What it does well
- 8 lb published for a 29 in case leaves 42 lb of payload inside a 50 lb checked cap
- The published warranty covers airline-caused damage for the first year, which almost nothing else does
- Expands 2 in, which is the return leg solved
What you give up
- 65 published linear inches is over the 62 in cap most US carriers apply to checked bags
- Softside means the shell protects contents less than a hard case would
- No manufacturer-published price to compute cost per covered year
The arithmetic behind the score
- Value not scored — No manufacturer-published price, so this axis is not scored.
- Airline-fit breadth 0.0/10 — Fits the published carry-on limit at 0 of 11 US carriers
- Carry efficiency not scored — No published capacity, so weight per liter cannot be computed.
- 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: Travelpro published specifications, compiled 3 September 2026. Travelpro publishes a 29 × 20.5 × 12.5 in case size and a 31 × 21 × 13 in overall size. The overall figure is the one an airline measures, and it sums to 65 linear inches. No manufacturer-published US price was readable on 4 September 2026.
4 · One or two trips a year on Southwest, Frontier or Allegiant
Amazon Basics Hardside Spinner (21 in)
Skip this one. Skip it if you fly Delta. Its published 21.6 x 14.9 x 10 in sums to 46.5 linear inches - over Delta's 45 in cabin cap - and it is over on depth as well. It is the clearest case in the ledger of a bag failing both tests at once.
A three-year warranty against a decade elsewhere is the whole story: this is the bag you buy when the trip is next week and the budget is fixed.
- Published size
- 21.6 × 14.9 × 10 in
- Weight
- 6.9 lb
- Capacity
- 39 L
- Weight per liter
- 0.18 lb/L
- Cost per covered year
- Not published
- Published list price
- Not published
Warranty Amazon Basics three-year limited warranty for luggage
Fits 4 of 11 US carriers: WN, F9, G4, SY. See the limits.
What it does well
- 21.6 in published height is under the 22 in standard
- 39 L published capacity at 6.9 lb, which is 0.18 lb per liter
- Built-in TSA lock on a bag at this tier
What you give up
- Three-year warranty is the shortest in this ledger by seven years
- 14.9 in width and 10 in depth both fail the standard box
- No repair route published — the remedy is replacement inside three years, then nothing
The arithmetic behind the score
- Value not scored — No manufacturer-published price, so this axis is not scored.
- Airline-fit breadth 3.6/10 — Fits the published carry-on limit at 4 of 11 US carriers: WN, F9, G4, SY
- Carry efficiency 4.9/10 — 6.9 lb ÷ 39 L = 0.177 lb/L
- Warranty & support 1.5/10 — 3 yr (1.5 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.
Specs: Amazon Basics published product specifications, compiled 3 September 2026. Sold only through Amazon, so its price is a live retail price rather than a manufacturer list price. We do not carry a number we have not verified live — check it on the day.
5 · Checked bags carrying anything that would not survive being stacked
Samsonite Winfield 3 DLX Large Spinner (28 in)
Polycarbonate protection for checked handling, at a published 10.96 lb — nearly 11 lb of your 50 lb allowance spent before you pack anything.
- Published size
- 30.5 × 20.5 × 13.25 in
- Weight
- 10.96 lb
- Capacity
- Not published
- Weight per liter
- Not published
- Cost per covered year
- $26.00/yr
- Published list price
- $259.99
Warranty Limited 10 year warranty against defects in materials and workmanship
Fits No US carrier in our table publishes a limit these dimensions satisfy. See the limits.
What it does well
- 100% polycarbonate flexes under the impacts a checked bag actually receives
- $25.99 per covered year on a published 10 year warranty
- 64.25 published linear inches is closer to the 62 in cap than most 28 in cases
What you give up
- 10.96 lb empty is 22% of a 50 lb checked allowance
- Still over the 62 linear inch cap most US carriers publish
- The published warranty covers defects, not airline handling damage
The arithmetic behind the score
- Value 3.9/10 — $259.99 ÷ 10 yr = $26.00/yr
- Airline-fit breadth 0.0/10 — Fits the published carry-on limit at 0 of 11 US carriers
- Carry efficiency not scored — No published capacity, so weight per liter cannot be computed.
- Warranty & support 4.0/10 — 10 yr (4 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.
Specs: Samsonite published specifications and price, compiled 3 September 2026. Samsonite publishes a 28 × 20 × 13.25 in packing size and a 30.5 × 20.5 × 13.25 in overall size. The overall figure sums to 64.25 linear inches.
No live price is currently verified, so every button here reads Check price on Amazon rather than a number we cannot stand behind. See how we handle prices.