Carry-on only travel is one of those travel skills that sounds restrictive until you try it — at which point most travellers wonder why they ever checked luggage. No baggage fees (significant on budget airlines), no waiting at baggage carousels, no risk of lost luggage, the ability to make same-day flight changes, and the freedom of being genuinely mobile. Here's exactly how Australians pack everything they need in a 40-litre carry-on.
The Carry-On Size Rules
This is where most Australians go wrong — carry-on allowances vary significantly between airlines. The strictest airlines (Jetstar, Scoot, AirAsia) limit carry-on to 7–10kg and check dimensions (56 × 36 × 23cm for Jetstar). Full-service airlines (Qantas, Singapore Airlines, Emirates) allow 7kg but rarely enforce dimensions strictly for soft-sided bags. If your trip involves budget carriers at any point, your carry-on must meet the strictest allowance on your itinerary.
The Osprey Farpoint 40 or Peak Design Travel Backpack 30L both meet most international carry-on size requirements. A hard-sided carry-on suitcase (Samsonite Lite-Box, Away Carry-On) is the alternative — better protection for electronics, easier to wheel, harder to force into overhead lockers on regional aircraft.
The Actual Packing List — 2 Weeks in Southeast Asia
Clothing (7 items total): 3 t-shirts (synthetic quick-dry fabric, not cotton — cotton takes 12+ hours to dry, synthetic takes 2), 1 long-sleeve shirt (sun protection on boats, temples, air-conditioned restaurants), 1 pair of shorts, 1 pair of lightweight pants (temple dress code, mosquito evenings), 1 swimsuit. This covers every scenario when combined with the quick-dry strategy: wash each day, dry overnight.
Shoes (2 pairs): Walking sandals (Birkenstock, Teva or Reef — also suitable for beach, restaurants and casual) and one pair of lightweight runners or slip-on shoes. Two pairs covers everything from hiking to dinners. Three pairs is where carry-on travel breaks down.
Electronics: Laptop or iPad (your actual need, not both), phone, universal adaptor (one small adapter, not a full travel power strip), portable battery pack, earphones, watch charger if applicable. The mistake: bringing electronics for every contingency rather than just what you'll actually use daily.
Toiletries: All under 100ml for airport security. Toothbrush, toothpaste, deodorant, sunscreen (buy a larger bottle on arrival in Bali or Bangkok — much cheaper), small shampoo (most accommodation provides it). The entire toiletries kit fits in a 1-litre zip-lock bag.
The Packing Cube System
Packing cubes are the single most impactful carry-on organisation tool. One cube for clothing, one for electronics, one for toiletries. When you arrive, you slide the cubes into drawers rather than unpacking item by item. When you leave, you slide them back. The main benefit: you always know where everything is, and re-packing takes 5 minutes rather than 30.
Eagle Creek, Osprey and Amazon basics all make good packing cubes. Compression cubes (squeeze handles reduce volume) work well for the clothing cube, allowing a larger clothing pack to compress to carry-on dimensions.
What to Do About Laundry
The carry-on only system depends on washing clothes every 2–3 days. In Southeast Asia this is trivially easy — AUD $3–5 for a bag of washing done same-day at any guesthouse or local laundry (everywhere). In Europe, hotel sink washing works well for synthetics overnight. A small packet of travel soap (Sea to Summit Trek & Travel Pocket Soap) allows sink washing even in accommodation without laundry services. The mental shift from "I need 14 outfits for 14 days" to "I need 3 outfits I wash every few days" makes carry-on only travel accessible.
The One Exception — Winter Travel
Carry-on only is harder for cold-weather destinations. A down jacket and ski gear genuinely don't compress into 40 litres alongside a week's worth of clothes. The workaround: wear the bulkiest items (jacket, boots) on the plane. Stuff the jacket into an overhead locker. This approach works for a ski trip or Japan in winter — the jacket travels as "worn clothing" not baggage.
The Capsule Wardrobe System for Travel
The most effective packing light system is building a travel capsule wardrobe where every item pairs with every other item. Five tops, two bottoms, one layer, one pair of shoes that works for everything -- this is the arithmetic of carry-on travel. The colour palette matters: neutrals (navy, grey, black, khaki) cross-match infinitely; a bright orange top does not. The classic carry-on wardrobe for a 2-week trip: three t-shirts, one long-sleeve shirt, one lightweight merino wool sweater (odour-resistant, temperature-regulating, works from plane to restaurant), one pair of versatile pants (not jeans -- too heavy and slow to dry), one pair of shorts, one dress or smart casual shirt, four pairs of underwear (merino or synthetic, wash overnight), three pairs of socks. Total clothing weight: 1.2-1.8kg.
The Gear That Makes It Work
A hanging toiletry bag keeps all toiletries organised and accessible at hostel or hotel bathroom facilities without unpacking. A 1-litre clear ziplock bag for liquid carry-ons (under 100ml per container, total 1 litre maximum for security) keeps security theatre manageable. Microfibre towel (300g versus bath towel 600-900g): most accommodation provides towels but camping and budget guesthouses do not. A small dry bag doubles as dirty laundry bag and waterproof beach bag. The packing cubes system means the bag can be repacked in 3 minutes regardless of how chaotic the departure was.
The Mindset Shift for Carry-On Travel
The most common objection to carry-on only travel is 'I just need more stuff.' This is almost universally false after the first trip. Experienced carry-on travellers consistently report washing one item per day (sink wash, dry overnight) eliminates the need for a full week's clothing. Most hotels provide shampoo and soap -- bring minimal toiletry bottles. Shoes are the main culprit: three pairs of shoes fills a bag faster than a week of clothing. One pair that handles walking, casual dining and the occasional dressier occasion is the carry-on compromise that makes everything else work. The first carry-on trip is the hardest; every subsequent trip produces further refinement.
The no-checked-bag guarantee -- arriving at any airport in the world with only carry-on -- eliminates baggage carousels, delayed luggage, and lost luggage permanently. Once converted, almost no frequent traveller voluntarily returns to checked baggage for leisure trips under three weeks. Every experienced carry-on traveller identifies the single trip that converted them permanently -- the moment they realised the bag was enough, that they had everything they needed, and that the absence of checked luggage was liberating rather than limiting.