The useful question for a seven-day trip is not how many shirts fit in the backpack. It is whether you can wash any of them. A laundry stop can change the packed load more than clever folding, but only if it fits your itinerary and leaves clothes dry before the next move.
Two ways to cover seven days
Without laundry, plan enough clean clothing for the week according to your activities and normal wearing habits. That may require more volume, especially if you exercise, change for dinner or prefer fresh pieces each day. There is nothing inherently wrong with that choice; account for it before selecting the bag.
With washing available, build a smaller rotation. As an example, a traveler could plan a wash midway through the stay, keeping an outfit available while the rest is being cleaned. The exact counts depend on what you rewear, the clothing material and how quickly you can get the wash finished. Do not assume that a booked apartment includes a working dryer.
The wash-day gap
Suppose your first four nights are in one place and the next three involve moving between hotels. A late wash on the fourth evening could leave wet clothing when you need to check out. Moving the wash earlier creates time to dry and repack, even if it means wearing one piece an additional time.
Check the accommodation information, and ask about laundry facilities when the answer matters to your packing plan. If you will use a service, allow for its return time. A sink-washing plan is only practical when the garment's care instructions, the available space and the accommodation's rules permit it.
Keep the week from multiplying
Choose clothing that works in more than one planned combination. Two bottoms and several compatible tops can offer flexibility without requiring seven separate outfits. This is an example of a method, not a recommended wardrobe for every traveler. A specialist event or personal requirement may deserve its own clothing.
Limit the number of hard-to-pack extras by giving each a role. If you bring walking shoes and a dressier pair, ask whether sandals are needed as well. If your phone covers your reading and navigation needs, another device may be optional. Keep the things you truly rely on rather than chasing someone else's minimalist count.
Choose capacity after the dry run
Lay the week's load out, pack it and include the final-day extras such as a charger and full water bottle. A roomy bag with little structure may carry that load worse than a slightly heavier bag with a suitable harness. Conversely, a large laptop compartment can occupy space you would rather use for clothes if you are traveling without a computer.
Keep a fallback for laundry disruption. That might be one extra change of essentials, an alternative laundry location or enough time to buy a needed item. It should be proportionate to the trip, not a second wardrobe. The goal is a bag whose contents support the week you planned while remaining manageable during transfers.
