The consumption rate of an item is the average daily quantity used, across both sales and non-sales loss. It is one of the most important inputs to replenishment math: PAR, reorder point, days of stock, and safety stock all derive from it.
Quick answers
What is the consumption rate? Consumption rate is how fast an item is used per day, combining direct sales (units sold) and non-sales loss (spoilage, shrinkage, breakage, internal use). It is measured in units per day per item.
How do you calculate the rate of consumption? For an item sold directly: consumption rate = sum of daily sales over last 30 days / 30. For an ingredient that goes into recipes: consumption rate = Σ (recipe sales rate × recipe yield for this ingredient). Add a decay factor for perishables.
What's the consumption rate formula for a restaurant ingredient? ingredient consumption rate = Σ (recipe sales rate × recipe yield). If a sandwich uses 100g of bread and you sell 30 sandwiches/day, the bread consumption from that recipe is 3 kg/day. Sum across all recipes that use the ingredient, then add decay.
Why use a 30-day rolling window? Too short (7 days) is noisy and over-reacts to weekly spikes. Too long (90+ days) under-reacts to trend changes and is stale through season changes. A 30-day window is a practical starting point: long enough for stable means, short enough to catch trend.
Components of consumption
observed usage rate = recorded usage units / observed days
modeled total depletion = non-decay usage + separately modeled loss
or, more practically: