Four days is the ideal duration for a city break and also the ideal test of whether you can travel carry-on only. You can. Almost everyone is packing more than they need.

The Case for Carry-On Only

No checked baggage fees. No waiting at the carousel. No risk of your bag going to the wrong city. You walk off the plane and go directly to the city. This alone saves 30-45 minutes at each end of the trip.

For budget airlines, carry-on only often makes the difference between a cheap flight and a moderately expensive one once you add a hold bag fee.

The 4-Day Clothing Formula

The mistake most people make is packing one outfit per day. Instead, pack versatile pieces that work across multiple days and combinations.

Tops: three. Not four. Three tops that mix and match with your bottoms. Lightweight fabrics that do not crease.

Bottoms: two. Trousers or jeans that work for sightseeing and a smart dinner. One pair of shorts if relevant to the destination and season.

One mid-layer: a merino wool jumper or a zip-up fleece. Merino is warm, lightweight, does not smell after multiple wears, and compresses well.

One outer layer: a packable rain jacket. For European city breaks this is rarely optional.

Smart option: if your trip includes one nice dinner, add a single versatile piece (a dress, a smarter shirt) that elevates your day clothes. Not an entire outfit.

Underwear and socks: four sets. You can hand-wash if needed but four days rarely requires it.

Shoes: The Weight Offender

Most people overpack shoes. One pair of comfortable walking shoes that look respectable enough for dinner. If you genuinely need smart shoes for a specific event, wear them on the plane and pack the casual ones.

Trainers double as walking and casual dinner in most European cities. Overpacking shoes kills a carry-on packing strategy faster than anything else.

Toiletries

Use travel-sized containers and refill them. Buy anything bulky (shampoo, conditioner) in a supermarket when you arrive. Take solids where possible: solid shampoo bars and deodorant bars avoid the 100ml liquid rule entirely.

Contact lens solution is the one liquid that gets people caught out — it counts against your 100ml allowance. Decant into a small travel bottle.

Packing Order

Shoes at the bottom, heaviest items next (jeans, laptop if relevant), clothes rolled rather than folded in the middle, small items in pockets and top layer. Packing cubes are not essential but they do make finding things faster without unpacking everything.

What You Do Not Need

A full hairdryer. Hotels provide them, Airbnb hosts usually do. A towel. Accommodation provides them. Multiple pairs of jeans. One is enough. Backup outfits "just in case." Just in case of what? Buy something if an emergency arises.