About this tool
Economic Order Quantity (EOQ) Calculator is a free, in-browser tool that finds the order size that minimizes your total inventory cost. Enter annual demand, the fixed cost of placing one order, and the cost of holding one unit for a year, and it returns the optimal quantity along with how often to order and the resulting annual cost. Nothing is uploaded.
EOQ uses the classic Wilson formula, EOQ = √(2·D·S ÷ H), where D is annual demand in units, S is the ordering cost per order, and H is the annual holding cost per unit. From that it derives orders per year = D ÷ EOQ, cycle time = 365 ÷ orders per year (days between orders), and the total annual inventory cost = (D ÷ EOQ)·S + (EOQ ÷ 2)·H, which balances ordering cost against holding cost.
Use it to set purchase-order sizes, cut carrying costs, or check a supplier's minimum order against the economically optimal one. Because the total-cost curve is flat near its minimum, ordering close to the EOQ is usually good enough in practice.