Order Quantity Simulator
Calculate optimal order quantity using the formula: Optimal Order Quantity = √((2 x Demand x Ordering Cost) / Holding Cost)
How to Calculate Optimal Order Quantity
The Economic Order Quantity (EOQ) formula minimizes total inventory costs:
- Demand: Annual demand for the product
- Ordering Cost: Cost to place an order
- Holding Cost: Cost to hold one unit for one year
- Optimal Order Quantity: Order size that minimizes total costs
Calculate Optimal Order Quantity
Order Quantity Visualization
Order Size Optimization
Cost Balance
Order Metrics
Annual Ordering Cost
Cost of placing orders annually
Annual Holding Cost
Cost of holding inventory annually
Total Cost
Sum of ordering and holding costs
Orders per Year
Number of orders annually
EOQ Analysis
Order Quantity Recommendations
Your optimal order quantity of 707 units will minimize total inventory costs at $1,414 annually.
- Place orders of 707 units approximately every 26 days
- This quantity balances ordering and holding costs effectively
- Consider seasonal variations in demand when placing orders
- Monitor actual demand to adjust order quantities accordingly
Understanding Economic Order Quantity (EOQ)
What is EOQ?
Economic Order Quantity (EOQ) is the optimal order quantity that minimizes total inventory costs by balancing ordering costs and holding costs.
The EOQ Formula
The standard EOQ formula is:
This calculates the order quantity that minimizes the sum of ordering and holding costs.
Key EOQ Assumptions
- Demand is constant: Known and uniform throughout the year
- Lead time is constant: Fixed time between ordering and receiving
- No stockouts: Sufficient inventory to meet all demand
- Instantaneous receipt: Complete delivery of orders at once
- Only relevant costs: Ordering and holding costs only
- No quantity discounts: Constant unit cost regardless of order size
EOQ Quiz
Question 1: Formula Understanding
According to the EOQ formula, what is under the square root?
According to the formula: EOQ = √((2 × Demand × Ordering Cost) / Holding Cost)
The expression (2 × Demand × Ordering Cost) / Holding Cost is under the square root.
The correct answer is a) (2 x Demand x Ordering Cost) / Holding Cost.
This question tests understanding of the EOQ formula structure. Remember that the numerator is 2 times the product of demand and ordering cost.
Economic Order Quantity (EOQ): The optimal order quantity that minimizes total inventory costs.
The EOQ formula has 2 in the numerator, multiplied by demand and ordering cost, then divided by holding cost, all under the square root.
Question 2: Real-World Calculation
If annual demand is 8,000 units, ordering cost is $40, and holding cost is $2 per unit, what is the EOQ?
Scenario Details:
- Annual Demand: 8,000 units
- Ordering Cost: $40
- Holding Cost: $2 per unit
Using the formula: EOQ = √((2 × Demand × Ordering Cost) / Holding Cost)
EOQ = √((2 × 8,000 × 40) / 2) = √(640,000 / 2) = √320,000 = 566 units
The optimal order quantity is 566 units.
Remember to take the square root of the entire fraction in the EOQ formula.
Q&A
Q: How often should I recalculate EOQ for my products?
A: The frequency of EOQ recalculations depends on how quickly your business conditions change:
Quarterly Recalculations:
- For products with stable demand and costs
- When market conditions are relatively constant
- For mature products with predictable patterns
Monthly Recalculations:
- For products with moderate demand fluctuations
- When costs are subject to seasonal changes
- For growing products with changing patterns
Trigger-Based Recalculations:
- Significant changes in supplier costs
- Major shifts in customer demand
- Changes in warehouse storage costs
- New products entering the market
Most e-commerce businesses recalculate EOQ quarterly for stable products and monthly for volatile products.
Q: What if my supplier offers quantity discounts? How does that affect EOQ?
A: Quantity discounts require a modified approach to EOQ calculation:
Steps to Handle Quantity Discounts:
- Calculate the standard EOQ without discounts
- Check if the EOQ falls within a discount bracket
- If not, calculate total costs at the minimum quantity for each discount bracket
- Select the order quantity that results in the lowest total cost
Modified Total Cost Formula:
Total Cost = (Annual Demand/Order Quantity × Ordering Cost) + (Order Quantity/2 × Holding Cost) + (Annual Demand × Unit Cost)
Example:
- Without discount: EOQ = 500 units at $10/unit
- With discount: 1000 units at $9/unit
- Calculate total cost for both scenarios and choose the lower one
Quantity discounts may make larger order quantities more economical than the standard EOQ.