Best Backpack for 5 Days Without a Checked Bag
Five days on hand luggage takes about 40 litres in a season needing bulky clothing, and about 30 in one that does not. The constraint is bulk rather than item count: two jumpers and a coat occupy more of a bag than five days of shirts do.
Why five days is the awkward number
Three days fits in almost anything. A week usually means a checked bag or a laundry plan. Five sits on the line, and which side of it a trip lands on depends almost entirely on the season. In summer, five days is shirts, underwear, one pair of trousers and a swimsuit, and 30 litres is comfortable. In winter the coat alone can occupy a quarter of a 40-litre bag.
The arithmetic
Work in bulk, not in items. A folded t-shirt is roughly a litre; a pair of trousers two to three; a fleece four to six; a puffer jacket eight to twelve. Shoes are the worst offenders at four to six litres a pair, which is why one pair worn and one packed is the standard rule. Add a laptop layer and a wash bag and a 40-litre bag is committed before the clothes go in.
Compression changes this arithmetic and only for the lofty items. Sealed and pumped, a coat and a fleece give back more than half the space they occupied — which is precisely the difference between three days and five in a cold month. It does nothing for the trousers, the books or the shoes.
What to reach for
For five days with bulky clothing, the 40-litre compression model is the answer in this range: the largest capacity here, with the compression that makes it go further. For five days in a warm season, the 30-litre carry-on is enough and easier to live with, because nothing has to be sealed or pumped.
If the allowance is a strict under-seat box rather than a cabin bag, neither is the right question — see the airline allowances first, because a bag that does not clear the sizer does not get to hold anything.
The capacity arithmetic is worked through in full in how many litres do you need.
Questions
What size backpack for 5 days?
About 40 litres when bulky clothing is involved, about 30 when it is not. Season decides it more than trip length does.
Can 30 litres cover five days?
In a warm season, comfortably. In winter, a coat and a fleece will take the space that would otherwise have carried two more days.
Does compression add days?
Effectively yes, on lofty clothing. It recovers more than half the volume of bulky items, which is often the difference between three days and five.
Do shoes have to travel?
One pair worn and one packed is the standard rule. A pair of shoes is four to six litres, which is a tenth of a 40-litre bag.