Sell-through by size compares units sold with the stock made available for each size during a defined period. It can show that a style’s medium sells differently from its large, but the result must be read alongside stockouts, returns and replenishment. A high rate is not automatically proof that the original size mix was ideal.

Choose one definition and period

A simple calculation is units sold divided by units available, multiplied by 100. Define “available” consistently. For a one-time buy, it may be beginning stock plus receipts during the period. If stock is transferred between locations, include those movements in the location-level record.

Use the same start and end dates for every size. Separate gross sales from net sales if returns are material, and label which measure appears in the report.

A worked example

Suppose a style begins with 20 medium units and receives 10 more. It sells 18 during the period. Using 30 available units, sell-through is 18 divided by 30, or 60%. If large begins with 10 and sells all 10, its rate is 100%, but it may also have lost further sales after stocking out.

Those numbers are illustrative. They show why percentages need the underlying quantities beside them.

Build a useful table

• Style, colour and size.
• Beginning stock and receipts.
• Transfers in and out.
• Gross units sold, returns and net units sold.
• Ending stock and stockout date, if any.
• Calculated sell-through percentage.

Separate demand from availability

A size that was unavailable for half the period had fewer opportunities to sell. Record days in stock or at least the first stockout date. Do not conclude that a size has low demand simply because it received little stock, nor assume 100% sell-through means its demand was fully satisfied.

Review colour and channel carefully

Size performance can differ by colour, store or online channel. Start with style-colour-size data, then aggregate only when the comparison remains meaningful. A combined result can hide that one colour carried most of the stock.

Use the result for the next decision

Compare several similar periods or styles before changing a core size ratio. Review customer fit feedback and return reasons alongside sales. For a reorder, document the proposed ratio and the evidence supporting it, then track the outcome in the next report.

When sourcing through Attirings wholesale, provide the planned size breakdown with your enquiry. Use our cost per saleable unit guide separately so demand and acquisition cost are not mixed into one measure.

Reconcile the calculation

Check that beginning stock plus receipts and transfers, minus net sales and adjustments, agrees with the ending count. Investigate unexplained differences before changing the next size order. A percentage built on unreconciled quantities can make a stock-recording problem look like customer demand.