What actually fits in a 20-inch carry-on

A 20-inch spinner gives you roughly 38 litres. The trick is not what you bring, it is how you compress it. Vacuum bags earn their space for anything puffy.

Roll, do not fold, and pack the heaviest items against the wheels so the case rolls instead of dragging. Shoes go in first, toe-to-heel, with a shower cap over the soles.

Keep a 'transit layer' accessible: the top pocket holds your liquids pouch, chargers, and one change of clothes in case the bag is gate-checked.