What is weeks of supply and how do I use it to plan markdowns?

Weeks of supply tells you how many weeks it will take to sell out of a particular style at your current selling pace. Calculate it by dividing your current quantity on hand by average weekly sales (which is total units sold divided by weeks the item has been on the floor).

The power of this metric comes from comparing it to the weeks remaining in your summer selling window. If a style has 10 weeks of supply but only 6 weeks left until Labor Day, it will not clear on its own and needs a markdown. If weeks of supply is smaller than weeks remaining, leave it alone — it's on track.

This comparison is the trigger for every tier decision in a markdown ladder. It removes emotion from the process and gives you a clear, data-driven answer to 'should I discount this?' Check it every Monday and let the numbers guide your moves.