It depends if you have an on-board washer/dryer. And how often you re-wear clothes before washing them.
If you have an on-board washer/dryer or re-wear things between washings, you need less.
We had what worked out to about a week’s worth of clothing per person.
We had a mix of cool to hot clothing and tried to avoid cold.
The onboard washer/dryer is love. We started without one and added it later. We wished we had added it sooner!