Free online calculator
Stockout Cost Calculator
Estimate lost contribution from missed sales plus additional costs caused by a stockout.. Includes a worked example, formula and practical FAQs.
Formula: Stockout cost = missed units × contribution per unit + additional costs
How to use the Stockout Cost Calculator
Estimate lost contribution from missed sales plus additional costs caused by a stockout.
Formula
Lost contribution = missed units × contribution per unit; stockout cost = lost contribution + additional costs.
Worked example
40 missed units at $12 contribution each lose $480 contribution. Adding $120 expedited handling or other incremental costs gives $600 estimated stockout cost.
Interpretation and limitations
Use contribution per unit rather than the full selling price to avoid treating avoided variable costs as a loss. Only include genuinely incremental additional costs.
Stockout Cost questions
Why not multiply missed units by sales price?
Revenue loss and profit impact differ. Unsold units may avoid some variable costs, so contribution is the relevant input here.
Does this capture lifetime customer loss?
No. Long-term customer effects need separate assumptions and should not be treated as measured losses without evidence.
Continue your calculation
For the next step, use the Safety Stock Calculator or the Contribution Margin Calculator. Review each tool’s input definitions before carrying a result into another calculation.
Frequently asked questions
Is this calculator free?
Yes. It runs in your browser and does not require an account.
How should I use the result?
Use the result as a planning estimate and verify business-critical decisions against your source records.