“Carry-on approved” means almost nothing — it usually refers to the US standard of 22 × 14 × 9 inches, and plenty of airlines, especially budget and international carriers, are stricter. Measure against your airline, including wheels and handles. The two specs that decide whether you like a bag are empty weight and usable interior volume, and hardside bags quietly lose volume to shell thickness and internal wheel housings that softside bags do not. A 6.6–7 lb bag around 40 litres suits most travellers.
Key takeaways
- 22 × 14 × 9 inches is the common US cabin limit — and it is not universal. Check your specific airline.
- Empty weight is the underrated spec. On a 10 kg allowance, a 7.5 lb bag consumes about a third of it before you pack anything.
- Hardside loses interior volume to shell thickness and internal wheel wells. Softside uses nearly the whole external envelope.
- Polycarbonate is more durable and scratch-resistant than ABS, and costs more.
- Expandable zips make the bag non-compliant when expanded. Useful for checked trips, a trap at the gate.
- Away’s Carry-On is 7.5 lbs at 21.7 × 14.4 × 9 with a limited lifetime warranty; lighter options exist at 6.6–6.9 lbs.
- Read what a “lifetime warranty” actually covers — wheels and zips are what fail, and they are sometimes excluded.
The size rules nobody reads until the gate
The 22 × 14 × 9 inch figure is the common maximum across many major US carriers, and it is what almost every bag sold in the US is designed against. Two things make it less reliable than it sounds.
First, the measurement includes everything. Wheels, handles, feet and any external pockets count. A bag advertised as “22 inches” is sometimes 22 inches of body plus an inch of wheels, which makes it 23 and non-compliant. Manufacturers who publish their dimensions including wheels — the way Away states 21.7 × 14.4 × 9 — are being straight with you.
Second, airlines differ, and the differences are not small. Budget carriers and many international airlines run tighter limits, and some enforce weight allowances that US domestic carriers largely ignore for cabin bags.
| Situation | What to check |
|---|---|
| US domestic, major carrier | 22 × 14 × 9 in; weight rarely enforced in cabin |
| Budget carrier (US or Europe) | Smaller dimensions; personal-item-only fares are common |
| European and Asian carriers | Often a weight limit of 7–10 kg, actively enforced |
| Regional jets | Smaller overhead bins regardless of the published limit |
The weight allowance trap
This is where empty weight becomes the most important number on the spec sheet, and it is the one buyers most often ignore.
On an airline enforcing a 10 kg (22 lb) cabin allowance, a 7.5 lb suitcase has consumed roughly a third of your allowance before you put anything in it. Drop to a 6.6 lb bag and you gain nearly a pound of packing. That is a pair of shoes.
If you fly mainly US domestic, weight matters less and you can prioritise durability. If you fly internationally or on budget carriers, weight may be the single most important specification.
Expandable zips
A lot of bags offer an expansion zip adding perhaps 20% capacity — 35L to 42L on some models. Genuinely useful on the return leg when you have bought things, and worth understanding clearly: an expanded carry-on is usually no longer within cabin dimensions. Expand it and you are planning to check it.
Hard shell or soft shell?
| Hard shell | Soft shell | |
|---|---|---|
| Protection | Better for fragile items | Less impact protection |
| Usable volume | Loses space to shell + wheel housings | Uses nearly the whole envelope |
| Overpacking | Rigid — what fits, fits | More forgiving; often expandable |
| External pockets | Usually none | Yes — laptop, documents |
| Weight | Varies; polycarbonate adds some | Often lighter |
| Water resistance | Better | Depends on fabric and coating |
| Ageing | Scuffs and cracks visibly | Frays and stains |
The volume point deserves emphasis
Two bags with identical external dimensions do not hold the same amount. A hardside case gives up interior space to the thickness of its shell and to the wheel housings that intrude into the packing cavity. A softside bag has thinner walls and typically mounts wheels externally, so it uses almost the entire external footprint for packing.
That is why a softside carry-on can offer 45 litres in the same external size where a hardside offers 35–42. If maximum packing capacity within a fixed limit is your priority, softside wins that argument on geometry.
Polycarbonate vs ABS
If you go hardside, the shell material matters. Polycarbonate is more durable and more scratch-resistant, and flexes under impact rather than cracking — it costs more. ABS is cheaper and lighter but more brittle over time. Many budget bags use an ABS/polycarbonate blend, which sits between the two.
Away’s Carry-On is 100% polycarbonate and weighs 7.5 lbs. The LIGHT FLIGHT at 6.6 lbs uses ABS and is nearly a pound lighter — a clean illustration of the trade between durability and weight.
Two wheels or four?
Four-wheel spinners glide beside you down a smooth terminal floor and take the weight off your shoulder entirely. Two-wheel rollers tilt and tow, handle broken pavement, cobbles and kerbs far better, and — this is the part rarely mentioned — their wheels are usually recessed into the body rather than protruding, so they intrude less on your dimension allowance.
- Mostly airports and hotels: spinner.
- European cities, cobbles, train platforms, uneven ground: two-wheel roller.
- Either way: wheels are the most common failure point on a suitcase. Check whether the warranty covers them.
What actually breaks
Suitcases rarely fail in the middle of a panel. They fail at wheels, zips and telescoping handles — the moving parts. When you read a “limited lifetime warranty,” the question worth answering before you buy is whether those three things are covered, and whether coverage means repair, replacement or a parts kit posted to you. Away offers a limited lifetime warranty on its Carry-On; the word doing the work in that phrase is limited, and reading the terms takes five minutes.
Zips
Look for chunky, self-repairing coil zips with double pulls, and check that the pulls take a TSA-approved lock. Built-in TSA combination locks — the kind on the BAGSMART — are more convenient than a padlock you will eventually lose, though no lock on a fabric bag stops a determined person with a pen.
What to buy
| You are… | Look for | Why |
|---|---|---|
| Flying budget or international | Softside, 6.6–7 lbs | Weight allowances are enforced; every pound of bag is a pound less of clothes |
| Packing fragile things | Polycarbonate hardside | Impact protection the fabric bags cannot match |
| Maximum capacity in the limit | Softside, ~45L | No shell thickness or internal wheel wells stealing volume |
| Working while you travel | External laptop pocket | Hardside cases have no outer pockets — everything means opening the case |
| Buying once for a decade | Polycarbonate + a warranty you have read | Durability and repairability, not the sticker price |
| Travelling with a child | Light bag, external pockets, two wheels | You are already carrying a person; every gram and every reachable pocket counts |
| Buying on a budget | ABS or blend, TSA lock, under 7 lbs | Sub-$100 bags are genuinely fine now; they just age faster |
Reference points from the current market
| Bag | Type | Weight | Notes |
|---|---|---|---|
| Away Carry-On | Hardside, 100% polycarbonate | 7.5 lbs | 21.7 × 14.4 × 9 in; limited lifetime warranty |
| LOVEVOOK 20″ | Softside | ~6.9 lbs | 45L — the volume argument for softside, in one number |
| BAGSMART | Softside, expandable | Under 7 lbs | 42L expanded; built-in TSA locks |
| LIGHT FLIGHT | Hardside, ABS | 6.6 lbs | 35L → 42L expandable; lightest here, least durable shell |
Note what that table shows: the lightest bag and the most capacious bag are both not the premium one. The Away buys you material quality, finish and a warranty — not weight or volume advantages.
Packing a carry-on so it actually works
- Roll, do not fold. Rolling removes air pockets and creases less. Compression cubes go further, though they add a few ounces of their own.
- Heavy items at the wheel end. The bag stands up properly and tows without tipping.
- Wear your bulkiest items. Coat and boots on your body are not in your allowance.
- Liquids in an accessible outer pocket if you have one — 3.4 oz / 100 ml containers in a quart bag, and you will be asked to remove it.
- One day of essentials in your personal item. Gate-checking happens on full flights whether or not your bag is compliant.
- Do not expand the expander unless you have accepted you are checking the bag.
- Weigh it at home if your airline enforces weight. A $12 luggage scale removes an entire category of airport anxiety.
The personal item is the real lever
Most airlines allow a carry-on and a personal item that fits under the seat. A well-chosen under-seat bag adds meaningful capacity for free, and it is where anything you actually need in flight should live — because once the cabin bag is in the overhead, it is effectively gone until landing.
Common mistakes
- Trusting “carry-on approved.” It is marketing. Check your airline’s published dimensions, including wheels.
- Ignoring empty weight. On a 10 kg allowance a 7.5 lb bag has eaten a third of it before you pack.
- Assuming equal external size means equal capacity. Hardside gives up volume to shell thickness and wheel housings.
- Expanding the expansion zip and heading to the gate. Expanded is usually non-compliant.
- Buying on brand. The lightest and the roomiest options here are not the most expensive one.
- Not reading the warranty. Wheels, zips and handles are what fail — check that those are covered.
- Overloading a softside because it stretches. It will fit and then it will not fit the sizer.
- Skipping the personal item. It is free capacity and it is the bag you can reach in flight.
Frequently asked questions
What size is a carry-on suitcase?
The common US standard is 22 × 14 × 9 inches, and that measurement includes wheels, handles and external pockets. It is not universal — budget carriers and many international airlines are stricter, and some enforce a weight limit of 7–10 kg that US domestic carriers usually ignore for cabin bags. Check your specific airline before you fly.
Is hardside or softside luggage better for carry-on?
Softside holds more within the same external dimensions, because hardside loses interior volume to shell thickness and internal wheel housings. Softside also has external pockets and is more forgiving when overpacked. Hardside protects fragile contents better and resists water. If maximum capacity matters most, choose softside; if protection matters most, choose hardside.
How much should a carry-on suitcase weigh?
Aim for 6.6 to 7.5 pounds empty. On an airline enforcing a 10 kg cabin allowance, a 7.5 lb bag uses roughly a third of it before you pack anything. Dropping to 6.6 lbs gains nearly a pound of contents — meaningful if you fly weight-restricted carriers.
Is polycarbonate or ABS better for luggage?
Polycarbonate is more durable and more scratch-resistant, and flexes under impact rather than cracking; it costs more. ABS is cheaper and lighter but more brittle over time. Many budget bags use a blend. If you are buying once for a decade, polycarbonate; if you want the lightest possible bag at a low price, ABS.
Should I get a two-wheel or four-wheel carry-on?
Four-wheel spinners are easier in smooth airport terminals and take the weight off your shoulder. Two-wheel rollers handle cobbles, kerbs and uneven ground far better, and their recessed wheels intrude less on your dimension allowance. Choose by where you actually walk, not where you board.
Do expandable carry-ons fit in the overhead bin?
Unexpanded, usually yes. Expanded, usually no — an expansion zip adds around 20% capacity and typically pushes the bag past cabin dimensions. Treat the expander as a feature for trips where you have accepted you will check the bag on the way home.
What does a lifetime warranty on luggage actually cover?
It varies enormously, which is why “limited” is the operative word. Suitcases fail at wheels, zips and telescoping handles, so those are what to check — whether they are covered, and whether coverage means repair, full replacement or a parts kit posted to you. Read the terms before buying, not after something breaks.
How many litres is a carry-on?
Roughly 35 to 45 litres within standard cabin dimensions. Softside bags reach the top of that range — around 45L — because they use nearly the whole external envelope, while hardside cases of identical outer size typically offer 35 to 42L.
Can I bring a carry-on and a personal item?
On most full-service airlines, yes — a cabin bag plus a personal item that fits under the seat in front of you. Some budget fares include only the personal item. The under-seat bag is where anything you need during the flight should go, since your overhead bag is effectively unreachable once the cabin fills.
How do I pack a carry-on to fit more?
Roll rather than fold, put heavy items at the wheel end so the bag stands and tows properly, wear your bulkiest coat and shoes, and use compression cubes if you are willing to accept their few ounces. Keep liquids in an accessible outer pocket in a quart bag with containers of 3.4 oz or less.