EOQ = √(2 × annual demand × cost per order ÷ holding cost per unit per year)
If you sell 1,800 units a year, each order costs you $50 to place and receive, and holding one unit for a year costs $2, then EOQ = √(2 × 1,800 × 50 ÷ 2) = 300 units per order.
EOQ balances the cost of ordering often against the cost of holding stock. Supplier minimums and case packs still apply on top of it.