Depletion rate is the rate at which inventory is consumed, sold or otherwise used over a defined period. In restaurants, it helps managers understand how quickly ingredients, beverages, packaging or operating supplies are being used and how much stock may be needed before the next delivery.
A basic usage-rate formula is:
Depletion rate = Quantity used ÷ Time period
If a kitchen uses 20 litres of fryer oil over five days, the average depletion rate is 4 litres per day. For a reliable figure, measure actual usage over a representative period and account for stock transfers, waste, spills, returns and changes in sales volume.
Compare average daily use with supplier lead time and expected demand. A basic reorder point can be based on expected usage during lead time plus an appropriate safety stock. Adjust the calculation for seasonality, menu changes, supplier reliability, shelf life and storage capacity. A rate based on an unusually quiet week may understate the stock required for a busy period.
Depletion rate measures the quantity used or sold over time. Inventory turnover measures how frequently inventory is sold or consumed and replenished over a broader accounting period, usually in relation to cost of goods sold and average inventory value.
Example: A restaurant records that a 20-litre container of fryer oil lasts five days at its normal sales volume. The resulting average use of 4 litres per day helps the chef plan the next order and investigate any unexpected increase.
Chef’s tip: Compare usage with sales or production. A higher depletion rate is not automatically waste; it may reflect higher volume, a menu change or a change in portion size.
Key distinction: Depletion rate describes the speed of inventory consumption. A reorder point uses that rate, lead time and safety stock to indicate when a new order should be placed.
This term is one of hundreds covered in depth across OCS courses, learning paths, and 1-on-1 coaching with Chef Eric.
