Economic Order Quantity (EOQ) Calculator

Calculate the optimal order quantity to minimize total inventory costs for your business. This tool helps small business owners, e-commerce sellers, and traders balance ordering and holding expenses. Use it to streamline supply chain decisions and reduce unnecessary overhead.

📦 Economic Order Quantity (EOQ) Calculator

Optimize inventory orders to minimize total costs

📊 EOQ Calculation Results

How to Use This Tool

Follow these steps to calculate your optimal Economic Order Quantity:

  1. Enter your total annual demand for the product in the Annual Demand field, then select the unit (Units, Dozens, Hundreds, or Thousands) from the dropdown.
  2. Input the fixed cost incurred each time you place a new order (e.g., shipping, processing, labor) in the Ordering Cost Per Order field.
  3. Enter the annual cost to hold one unit of inventory for a full year (e.g., storage, insurance, depreciation) in the Annual Holding Cost Per Unit field.
  4. Select your preferred currency from the Currency dropdown to display cost results in your local denomination.
  5. Click the Calculate EOQ button to generate your results. Use the Reset button to clear all inputs and start over.
  6. Click Copy Results to Clipboard to save your calculation breakdown for records or sharing.

Formula and Logic

The Economic Order Quantity (EOQ) is derived from the standard EOQ model, which minimizes total inventory costs by balancing ordering and holding expenses. The core formula is:

EOQ = √(2DS / H)

Where:

  • D = Annual demand in units
  • S = Fixed ordering cost per order
  • H = Annual holding cost per unit

This tool first converts your demand input to total units using the selected demand unit multiplier, then applies the formula to calculate EOQ in both your selected demand unit and base units. Additional metrics are calculated as follows:

  • Number of Orders Per Year = Annual Demand / EOQ
  • Annual Ordering Cost = Number of Orders × Ordering Cost Per Order
  • Annual Holding Cost = (EOQ / 2) × Holding Cost Per Unit
  • Total Annual Inventory Cost = Annual Ordering Cost + Annual Holding Cost
  • Average Inventory Level = EOQ / 2

Practical Notes

When using EOQ calculations for real-world business operations, keep these trade-specific considerations in mind:

  • EOQ assumes constant demand and fixed ordering/holding costs. Adjust calculations if you experience seasonal demand spikes or variable supplier pricing.
  • For e-commerce sellers, include marketplace fees, packaging costs, and inbound shipping in your ordering cost calculations.
  • Holding costs should account for warehouse rent, insurance, spoilage (for perishable goods), and opportunity cost of tied-up capital.
  • If you qualify for volume discounts from suppliers, compare EOQ results with discounted bulk pricing to find the true cost minimum.
  • Small businesses with limited storage space may need to cap order quantities below EOQ to avoid overstocking.
  • Traders dealing with international goods should include import duties, tariffs, and customs processing fees in ordering costs.

Why This Tool Is Useful

EOQ is a core supply chain metric for businesses of all sizes, and this tool simplifies complex calculations for non-specialists:

  • Reduces overstocking and understocking risks by identifying the mathematically optimal order size.
  • Lowers total inventory costs by balancing the tradeoff between frequent small orders and infrequent large orders.
  • Helps e-commerce sellers and small business owners make data-driven purchasing decisions without expensive ERP software.
  • Provides a detailed cost breakdown to share with stakeholders, suppliers, or accounting teams.
  • Supports multiple currencies and demand units to accommodate global trade and diverse product types.

Frequently Asked Questions

What if my ordering or holding costs change over time?

EOQ is a static calculation based on fixed inputs. If your costs fluctuate, recalculate EOQ quarterly or when major cost changes occur to keep your order quantities optimized.

Does EOQ account for lead time or safety stock?

No, the standard EOQ model does not include lead time or safety stock. To account for these, calculate your reorder point separately as: (Daily Demand × Lead Time) + Safety Stock, and place orders when inventory hits this level.

Can I use this tool for perishable goods?

Yes, but you must adjust your holding cost to include spoilage and waste expenses. For goods with very short shelf lives, EOQ may be less useful, and you should prioritize turnover rate over bulk ordering.

Additional Guidance

To get the most accurate results from this calculator, follow these best practices:

  • Review your past 12 months of order and inventory data to get precise demand and cost figures, rather than estimating.
  • Separate fixed ordering costs (e.g., labor, processing fees) from variable costs (e.g., per-unit shipping) when inputting ordering cost.
  • For businesses with multiple warehouses, calculate EOQ separately for each storage location to account for varying holding costs.
  • Compare your current order quantity to the calculated EOQ to identify potential cost savings opportunities.
  • Revisit your EOQ calculation annually, or whenever your business scales up, adds new products, or changes suppliers.