Why carry-on only is worth the effort
Airlines charge €30–80 per checked bag on most European routes. Over the course of a year of regular travel, that's hundreds of euros. But the financial saving is almost secondary to the time saving — skipping check-in, skipping baggage claim, and walking straight off the plane to ground transport is consistently 45–90 minutes faster than checking luggage.
The challenge is that most people pack for the worst possible outcome. They bring clothing for every weather scenario, toiletries for every eventuality, and tech for every situation. The carry-on system works by making a different decision: you pack for the most likely scenario, and you solve edge cases a different way.
The carry-on constraint: Most European airlines allow a cabin bag of approximately 55×40×23cm and around 10kg. Budget airlines (Ryanair, easyJet) are more restrictive — often 40×20×25cm. Always check your specific airline's policy before packing.
The clothing system: 1-2-3-4-5
The most reliable carry-on clothing system is simple enough to remember and flexible enough to work for almost any trip of up to 10 days:
- 1 hat — sun hat or baseball cap
- 2 shoes — comfortable walking shoes + one smarter pair (sandals or low heels)
- 3 bottoms — 2 trousers/jeans + 1 shorts or skirt
- 4 tops — 3 casual + 1 smarter for evenings
- 5 sets of underwear and socks
This covers 7 days with one laundry cycle mid-trip. Dark jeans are the workhorse — they look smart enough for any restaurant, casual enough for sightseeing, and they take up less space rolled than almost any other trouser.
Merino wool t-shirts can be worn 2–3 times between washes without smelling. Three merino tops replace five cotton ones in terms of actual wearable days. The upfront cost is higher — but the space saving is significant.
The toiletry limit: 100ml, 20 items maximum
Flying carry-on means the EU liquids rule applies: all liquids in containers of 100ml or less, all fitting in one transparent 1-litre bag. This is actually a useful constraint. It forces you to be selective, and it means you can never pack too many toiletries.
The items that are worth buying in travel sizes or solid form:
- Shampoo and conditioner — solid bars take zero liquid allowance and last weeks
- Toothpaste — travel size is widely available and lasts a week easily
- Sunscreen — buy a full-size bottle at your destination rather than cramming a 100ml travel size
- Deodorant — solid or crystal deodorant takes no liquid space
Anything you've forgotten can almost always be bought at a pharmacy or supermarket within 30 minutes of arriving. The exception: prescription medication, contact lens solution in your specific brand, and any niche product you rely on.
The tech stack: what's worth the weight
Tech is where carry-on packers consistently overpack. A laptop, tablet, e-reader, camera, and all associated cables adds up to 3–4kg before you've packed a single item of clothing.
The carry-on tech question is: what do you actually use on this type of trip? For a city break or beach holiday, most people's phone does everything they need a laptop for. For a work trip, a laptop is non-negotiable. For a photography trip, the camera is the priority and the laptop might be worth its weight for backup purposes.
Whatever you decide to bring, invest in a good multi-port USB-C charger (one device instead of three) and a short cable organiser pouch. Cables untangled and chargers organised save time twice a day in hotel rooms.
Build your personalised carry-on checklist
Our free tool builds a checklist for your specific trip type, duration and transport — including a carry-on mode that flags everything that might not make it through security.
✨ Build my list — freeThe things people always forget
Carry-on packers who've done it before tend to forget the same things repeatedly — not because they're forgetful, but because these items are easy to assume are in the bag and hard to notice are missing until you need them:
- Travel adapter — easily left in the hotel room from the last trip
- Earplugs and eye mask — massively underrated for long flights and noisy hotels
- A reusable bag — for groceries, beach days, and overflow when you buy things
- Paracetamol — airport pharmacies charge 3× the normal price
- Printed hotel address — for showing taxi drivers when you have no data roaming
The three non-negotiable rules
After stripping carry-on packing back to its fundamentals, three rules always hold:
- If you haven't worn it in the last month, you won't wear it on this trip. The "just in case" items take up the space that the items you'll actually use need.
- Roll, don't fold. Rolling saves approximately 20–30% space for most clothing items and reduces creases in lightweight fabrics.
- Pack the bag, then remove one item. Whatever you take out last is almost certainly something you'd have been fine without.