How to use the Economic Order Quantity Calculator
- Enter Demand per period as the number of units used or sold during the period you are analyzing.
- Enter Ordering cost per order as the fixed cost of placing one order.
- Enter Holding cost per unit per period for the same time basis as your demand.
- Choose the currency symbol, then select Calculate EOQ.
- Review the calculated figures and the intermediate values shown in the result table.
Enter the calculator inputs
Use compatible periods for demand and holding cost, such as annual demand with annual holding cost. The calculator uses the numeric values you enter and does not fetch supplier or market data.
Each numeric input must be greater than zero. If a value is missing, invalid, or not greater than zero, the calculator stops and shows an error instead of calculating.
Read the calculated results
The result includes these headline values:
- Economic order quantity (units/order)
- Orders per period
- Total inventory cost for the entered period
The table also shows the entered numeric inputs, the EOQ, orders per period, time between orders, ordering cost total, holding cost total, and total inventory cost. The calculation uses parsed input values; displayed numbers and money values are formatted to a maximum of two decimal places.
The calculator applies these formulas:
EOQ = √(2 × Demand × Ordering cost ÷ Holding cost)Orders per period = Demand ÷ EOQTotal inventory cost = (Orders per period × Ordering cost) + (EOQ ÷ 2 × Holding cost)
Copy or download the result
Select Copy result to place the plain-text summary on the browser clipboard. If clipboard access fails, the tool displays Could not copy - select and copy manually. Select Download result (.txt) to save the summary as a .txt file.
Calculation limits and assumptions
- Period is whatever your demand figure covers: keep demand and holding cost on a consistent time basis.
- Demand is constant and known: the model assumes a steady, predictable usage rate with no seasonality, spikes, or stockouts.
- Ordering cost is fixed per order: it does not change with order size, and no volume discounts on purchase price are modeled.
- Holding cost is constant per unit: it applies uniformly regardless of how much stock is on hand, and average inventory is assumed to be EOQ ÷ 2.
- No lead time or safety stock: the calculation does not model replenishment lead time, safety stock, or stockout costs - it only balances ordering cost against holding cost.
- Currency is a label, not a conversion: the currency symbol you pick is displayed on the result but no conversion or live exchange rate is applied - the output is in the same unit as your input.
- Period output label: the headline and table report the inventory cost for the same period covered by your demand and holding-cost inputs.
Privacy & Security
The calculator's calculation script processes the entered values locally in your browser and contains no tool-side upload or fetch logic. This describes the calculation process, not all network activity on the page.
Frequently Asked Questions
What is economic order quantity (EOQ)?
Economic order quantity is the order size that minimizes the total cost of ordering and holding inventory over a period, balancing the fixed cost of placing orders against the cost of holding stock.
What is the EOQ formula?
EOQ = square root of (2 x Demand x Ordering cost per order / Holding cost per unit per period). It is the point where total ordering cost equals total holding cost for the period.
What units should demand, ordering cost, and holding cost use?
Demand should be the number of units used or sold over a period (commonly a year). Ordering cost is the fixed cost of placing one order, and holding cost is the cost of storing one unit for that same period. Keep all three inputs on the same time basis, such as annual demand with an annual holding cost.
Why must demand, ordering cost, and holding cost all be greater than zero?
The EOQ formula divides by holding cost and takes a square root of the result, so a zero or negative demand, ordering cost, or holding cost makes the formula undefined or meaningless. The calculator blocks these cases with a validation error.
Does this tool fetch live prices or give personalized inventory advice?
No. It performs a single, transparent calculation using only the numbers you type in - demand, ordering cost, and holding cost. It does not fetch supplier prices, market data, or inventory records, and it is not personalized business or inventory advice.