Fill Rate

Fill rate is the percentage of customer orders fulfilled completely from available stock without any backorders or lost sales. It measures a company's ability to meet customer demand immediately from on-hand inventory. A high fill rate indicates effective inventory management and strong product availability, while a low fill rate suggests stockouts and potential customer dissatisfaction.

Why it matters for e-commerce brands

For Shopify and DTC merchants, fill rate directly impacts customer satisfaction, repeat purchase rates, and brand reputation. When products are out of stock, customers often abandon their carts or switch to competitors, resulting in immediate lost revenue and long-term customer attrition. Maintaining a high fill rate helps e-commerce brands build trust, reduce customer service inquiries about backorders, and maximize sales during peak seasons when demand surges.

Example

A Shopify apparel brand receives 500 orders in a week. Of these orders, 475 are fulfilled completely from warehouse stock and shipped immediately, while 25 orders contain at least one item that is out of stock and must be backordered. The brand's fill rate for that week is 95% (475 complete orders ÷ 500 total orders). If the brand notices their fill rate dropping below their target of 97%, they might investigate which SKUs are causing stockouts and adjust their reorder points or safety stock levels accordingly.

Related terms

• In-stock rate
• Order fulfillment rate
• Backorder
• Safety stock
• Inventory turnover