Choose a real interval
Set laundry to zero unless you expect access to a machine or a workable hand-wash routine. An interval of four means the planner estimates four days of wear before washing, capped at the trip length. It then adds one spare to tops, underwear, and socks.
Laundry access, drying time, and garment care matter. A number in the tool does not guarantee clothes will be clean and dry when you need them.
Check the itinerary
Place possible laundry sessions on the calendar. A long transfer day or late arrival is a poor time to depend on washing. If the trip includes consecutive active days, choose an interval that leaves room for those constraints.
When a hotel or rental advertises laundry, confirm what is actually available and whether access has limits.
Understand the formulas
The cycle is the smaller of trip days and the laundry interval, except that zero uses the full trip. Bottoms start at one per two cycle days plus a spare. Sleepwear starts at one per four cycle days, with a minimum of one set.
If your habits differ, use the displayed quantities as a baseline and change the final checklist. The formulas are deliberately visible so you can disagree with them.
Leave a recovery option
A spare clothing set can help when a wash is delayed, but it does not solve every interruption. Check whether you can buy or borrow a needed item at the destination if necessary.
After the trip, compare what you packed with what you wore. Adjust the interval and category assumptions for your next list.
Have a correction or a suggestion? Tell the studio.