The First Formula
a) Figure out my laundry cycle. What's the longest number of days something might sit in the hamper before it's ready to be worn again?
b) Calculate the percentage of days that I need to be able to wear this type of item.
c) Estimate how many days I can wear something before washing it. (When I had babies, I would estimate how many changes of clothes I needed per day.)
Multiply a and b, and then divide by c. Or if you are a mother of preschoolers that last operation would be a multiply. I hope you get it. I need to go shopping.