Canonical: https://ai.allesclinx.com/metricon/consumables-reorder-calculator Description: Calculate a consumables reorder trigger, target stock and whole-pack purchase quantity from daily usage, lead time, reserve and incoming orders. [Back to Metricon]() Metricon · Brand tools # Consumables reorder calculator Plan a reorder trigger and whole-pack purchase quantity from actual usage, lead time, reserve stock and incoming orders. Calculator Sources, assumptions & review User input **Values you provide** Check units, basis and local values before relying on the output. Calculated **Transparent model output** Metricon applies the displayed formula to the inputs on this page. Assumption **Model boundary** Scenario inputs and defaults are not measured facts unless you supplied them from a controlled source. Review **Human decision** Compare the result with approved product directions, actual operating conditions and accountable judgement. Formula `Reorder point = daily usage × lead time + reserve · Target = usage × (lead time + review interval) + reserve` Quantity unit Name the unit used for every stock quantity, such as litres, rolls or pieces. It is included in your memo. Average daily usage Use the same quantity unit throughout: litres, rolls, pieces or another chosen unit. Supplier lead time Days from ordering to usable receipt; use your actual supplier experience. days Replenishment review interval Days between planned stock reviews. This determines the target stock horizon. days Reserve stock Reserve in your chosen unit. It is an explicit assumption, not a calculated service-level buffer. Usable stock on hand Exclude expired, damaged or unavailable stock. Confirmed incoming quantity Same unit; include only orders expected within the planning horizon. Quantity per purchasable pack Same unit, such as 5 litres, 6 rolls or 100 pieces per pack. Stock review **—** **Before using the result** Keep usage, stock, reserve, incoming quantity and pack size in one unit. The model assumes stable average demand and usable incoming orders within the horizon. Timing can still create shortages; verify delivery dates and expiry. Zero demand needs review rather than an automatic purchase decision. ## How it works ### Choose one stock unit Keep daily usage, reserve, usable stock, on-order quantity and pack size in the same unit. Use measured consumption for the relevant item. ### Enter the replenishment timing Enter delivery lead days and review days. Add your chosen reserve quantity rather than treating it as a percentage. ### Review trigger and target Compare stock plus on-order quantity with the reorder point. The target also covers the review period; the model rounds any target shortfall up to whole packs. ### Check before ordering Review demand changes, supplier dates and whether incoming stock will arrive in time. Use the result to plan a purchase rather than treating it as an automatic order. ## Frequently asked questions How do the reorder point and target differ? The reorder point covers daily usage during lead time plus reserve. The target covers lead time and the review period plus reserve. Review is due when stock position is at or below the reorder point. What does stock position include? Usable stock plus the on-order quantity you enter. The model does not schedule individual deliveries or confirm availability, so check arrival dates and exclude unusable stock. Why is the purchase quantity rounded up? A positive target shortfall is divided by pack size and rounded up to whole packs. Zero daily usage is flagged for demand review; reserve and incoming-stock assumptions still need checking.