Do you need a separate daypack on a one-bag trip?
Usually yes, but it can be small. A second, smaller bag for days out lets the main pack stay at the hotel: a packable daypack of about 10–20 liters, a sling, or a small backpack that doubles as the personal item on the plane. Pick it by what you carry on an ordinary day.
Why bother with a second bag
Your main bag is for travel days. On a normal day out you want water, a layer, maybe a camera, and your phone and wallet, not a week of clothes. Many museums and some attractions also make you check large backpacks, and a big bag is tiring in crowds and on public transport.
The four common setups
- Packable daypack (about 10–20 L). Folds into its own pocket and weighs very little. Fine for water, a jacket, and snacks. Thin straps and no structure, so it gets uncomfortable with a laptop or a heavy load.
- Sling or crossbody bag (about 3–10 L). Phone, wallet, power bank, sunglasses, maybe a small umbrella. Easy to swing to the front in crowds. Too small for a jacket and a big water bottle together.
- Small backpack (about 15–25 L) as your personal item. Comfortable all day and can hold a laptop. It doesn’t fold away, so if your fare allows only one cabin bag, it has to squeeze inside the main pack and costs real space.
- No second bag. A tote, a foldable shopping bag, or just pockets. Works for warm city trips where you carry little.
How to choose
Lay out what you actually carry on a typical day out at home or on your last trip. Then ask:
- Does it need to hold a rain jacket or a warm layer? If yes, a sling is usually too small.
- Will you walk for hours with a camera or water? Then comfort matters more than packability.
- Is it also your personal item on the plane? Then check it against your airline’s under-seat size (see personal item vs carry-on).
- Is it hot where you are going? A sling keeps your back cooler than a daypack.
Two combinations work well: a packable daypack plus a tiny sling, or a single 15–20 L daypack that also does airport duty.
How much space it takes in the main bag
A packable daypack folds to about the size of a fist. A sling or small backpack doesn’t fold, so it costs real space. A 10 L sling packed inside a 40 L bag uses about a quarter of the volume, though you can fill the sling with socks or chargers so the space isn’t wasted.
On fares that include a personal item, the simplest move is to carry the small bag on the plane with your in-flight things and not pack it at all. On personal-item-only fares, the daypack is the whole luggage, and packing with only a personal item applies.
Crowds and pickpockets
Wear a sling across the front in busy places, keep zips closed and facing your body, and keep the phone in an inside pocket rather than an outer one. A daypack with a zipped pocket against your back is harder to get into than a front pocket. None of this makes theft impossible; it just makes you a less easy target.
Choose it with the main bag
If you are buying a new travel backpack, decide on the second bag at the same time, since it changes how much main-bag space you need. The deep guide on how to choose a carry-on travel backpack covers the main bag; for rainy trips, see what rain gear to pack.
General packing guidance only. Bag rules at museums and attractions vary; check before you go. Airline personal-item sizes vary by airline and fare.
FAQ
What size daypack is best for city travel?
About 10–20 liters covers most days out. That holds water, a layer, snacks, and a small camera. Go smaller if you only carry a phone and wallet, larger if you carry a laptop every day.
Is a sling enough instead of a daypack?
For warm city days with few things, yes. A sling usually can’t fit a rain jacket, a warm layer, and a full water bottle together, so pair it with a packable daypack if your days need more.
Can my daypack be my personal item?
Yes, if it fits your airline’s personal-item dimensions and slides under the seat. That’s the simplest setup on fares that include a personal item.
Do packable daypacks hold up?
They are fine for light loads like water, a jacket, and snacks. Thin straps and fabric make them uncomfortable and more prone to wear with heavy items like laptops.