Definition
Sell-through rate measures how much of a buy sold in a period: units sold ÷ units received (or opening stock + receipts), as a percentage. It is not the same as inventory turnover.
Formula
Sell-through % = units sold ÷ units available in period × 100
Worked example
You received 1,000 units for a launch month and sold 720 → 72% sell-through. The remaining 280 need a plan (promo, bundle, or slower reorder).
Why it matters for replenishment
Strong sell-through funds the next PO. Weak sell-through with high DOI signals overstock before it becomes dead stock.