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Stockout Cost Calculator
Estimate missed sales revenue and gross profit during a stockout using unavailable days, daily demand, selling price and unit cost.
What does this calculator measure?
Stockout cost in this calculator is an estimate of gross profit missed when demand cannot be fulfilled. It also shows missed revenue. The model assumes every unit of expected demand during the stockout is permanently lost.
Enter your figures
Use one consistent period. Calculations run locally in your browser.
Average demand on days the product would otherwise be available.
Days unavailable, using the same day basis as demand.
Net price after discounts, excluding collected sales tax.
Product cost in the same currency as selling price.
Your result
Fill in all fields or load the worked example to see your result.
Put your figures to work
Review low stock levels and purchasing records for products where stockouts interrupt sales.
Start managing inventoryFormula and worked example
Estimated lost units = Daily demand × Stockout days. Missed revenue = Lost units × Selling price. Missed gross profit = Lost units × (Selling price − Unit cost).
At 10 units per day for a 3-day stockout, estimated lost demand is 30 units. With a selling price of 50 and unit cost of 30, missed revenue is 1,500 and missed gross profit is 600.
How to use the calculator
- Choose the product, category or business and the period you want to review.
- Enter the figures described beside each field using consistent units.
- Review the result alongside the assumptions below before changing purchasing or stock plans.
How to interpret your result
This scenario excludes customer switching, later purchases, substitute products, additional shipping charges and long-term customer loss. If customers wait and buy later, the estimate overstates permanent lost sales. When price is below cost, missed gross profit is negative; that signals the assumed sale itself has a negative gross contribution.
Explore the inventory workflow in My Inventory ItemsFrequently asked questions
Is missed revenue the cost of a stockout?
Missed revenue is the sales amount you may have lost. Missed gross profit deducts product cost and is a different measure. Neither includes all operational or long-term consequences.
Does this account for customers buying later?
No. It assumes expected demand is permanently lost. Use a lower demand input if you are modeling only demand that will not be recovered.
Can I use fractional daily demand?
Yes. Average demand can be fractional, even when actual sales occur in whole units. The lost-unit result is an expectation rather than a physical count.