# Economic Order Quantity (EOQ): Key Insights for Efficient Inventory Management

## What Is Economic Order Quantity (EOQ)?

Economic order quantity (EOQ) is a vital [inventory](https://www.investopedia.com/terms/i/inventory.asp) management tool that helps businesses determine the optimal number of units to order to satisfy customer demand while minimizing associated costs like holding, order, and shortage costs.

Originally developed in 1913 by Ford W. Harris, the EOQ model has evolved to assist companies in maintaining financial efficiency. Understanding EOQ enables businesses to strategically control cash flow tied up in inventory, ensuring they meet customer demand without overburdening storage resources.

### Key Takeaways

*   Economic Order Quantity (EOQ) is a formula businesses use to determine the ideal order size that minimizes total inventory costs, including holding, ordering, and shortage costs.
*   By using EOQ, companies can effectively manage cash flow, as it helps to minimize the amount of cash tied up in inventory, which can be reallocated for other business purposes.
*   EOQ is particularly valuable for companies with significant inventory needs, ensuring they do not overstock or run out of stock, thus maintaining customer satisfaction and preventing lost sales.
*   The formula assumes constant consumer demand and stable ordering and holding costs, which can limit its accuracy during times of fluctuating demand or variable costs.
*   Adjusting for setup costs, product demand, and holding costs can change the EOQ, highlighting its flexibility to suit different business environments and needs.

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*— Investopedia / Jessica Olah*

## Understanding the Economic Order Quantity (EOQ) Formula

The formula for EOQ is:

> $\begin{aligned} &Q = \sqrt{ \frac{2DS}{H} }\\ &\textbf{where:}\\ &Q=\text{EOQ units}\\ &D=\text{Demand in units (typically on an annual basis)}\\ &S=\text{Order cost (per purchase order)}\\ &H=\text{Holding costs (per unit, per year)}\\ \end{aligned}$  
> 
> ## Insights Gained From Economic Order Quantity (EOQ)
> 
> The goal of the EOQ formula is to identify the optimal number of product units to order. If achieved, a company can minimize its costs for buying, delivering, and storing units. The EOQ formula can be modified to determine different production levels or order intervals, and corporations with large [supply chains](https://www.investopedia.com/terms/s/supplychain.asp) and high variable costs use an algorithm in their computer software to determine EOQ.
> 
> EOQ is crucial for managing [cash flow](https://www.investopedia.com/terms/c/cashflow.asp). The formula helps control how much cash is tied up in inventory.
> 
> For many companies, inventory is their largest asset after human resources, and they must maintain enough inventory to meet customer needs. EOQ minimizes inventory levels, freeing cash for other business uses or investments.
> 
> The EOQ formula [determines the inventory reorder point](https://www.investopedia.com/ask/answers/052715/how-economic-order-quantity-model-used-inventory-management.asp) of a company. When inventory hits a certain level, applying the EOQ formula signals the need to reorder.
> 
> By determining a reorder point, the business avoids running out of inventory and can continue to fill customer orders. If the company runs out of inventory, there is a shortage cost, which is the revenue lost because the company has insufficient inventory to fill an order. An inventory shortage can also mean losing customers or reduced future orders.  
>   
> 
> ## Practical Example of Applying Economic Order Quantity (EOQ)
> 
> EOQ considers reorder timing, order costs, and storage costs. Frequent small orders increase ordering costs and require more storage space.
> 
> Assume, for example, that a retail clothing shop carries a line of men’s jeans, and the shop sells 1,000 pairs of jeans each year. It costs the company $5 per year to hold a pair of jeans in inventory, and the fixed cost to place an order is $2.
> 
> The EOQ formula is the square root of (2 x 1,000 pairs x $2 order cost) / ($5 holding cost) or 28.3 with rounding. The ideal order size to minimize costs and meet customer demand is slightly more than 28 pairs of jeans. A more complex portion of the EOQ formula provides the reorder point.
> 
> ## Recognizing the Limitations of Economic Order Quantity (EOQ)
> 
> The EOQ formula assumes constant consumer demand. The calculation also assumes that both ordering and holding costs remain constant.
> 
> This fact makes it difficult or impossible for the formula to account for business events such as changing consumer demand, seasonal changes in inventory costs, lost sales revenue due to inventory shortages, or purchase discounts a company might realize for buying inventory in larger quantities.  
> 
> ## What Is the Economic Order Quantity?
> 
> Economic order quantity is an inventory management technique that helps make [efficient inventory management](https://www.investopedia.com/best-inventory-management-software-5088863) decisions. It refers to the optimal amount of inventory a company should purchase in order to meet its demand while minimizing its holding and storage costs. One of the important limitations of the economic order quantity is that it assumes the demand for the company’s products is constant over time.
> 
> ## When Is Economic Order Quantity High and Low?
> 
> EOQ increases with higher setup costs or product demand. On the other hand, it will be lower if the company’s holding costs increase.
> 
> ## Why Is Economic Order Quantity Important?
> 
> EOQ is important because it aids efficient inventory management. Without [inventory management techniques](https://www.investopedia.com/terms/d/drift.asp) such as these, companies will tend to hold too much inventory during periods of low demand while also holding too little inventory during periods of high demand. Either problem creates missed opportunities.
> 
> ## The Bottom Line
> 
> Managing inventory is a key component of success for a company. Having too much inventory results in higher costs that take away from profits due to the cost of maintaining inventory and sometimes having to discard old inventory. Having too little inventory means a company is losing out on sales by not meeting demand. Economic order quantity helps ensure companies manage their inventories efficiently.