Free inventory loss tool
Stockout Cost Calculator
Estimate the immediate sales and profit lost when an item is unavailable, plus the future customer value at risk when buyers do not return.
Simple stockout cost
Single stockout eventEstimate missed demand
Demand & duration
Unit economics
Customer value
Simple methodMissed units = daily demand × stockout days. Recovered demand is removed from permanent lost sales. Immediate economic loss uses lost gross profit, not lost revenue, then adds expected future customer gross profit lost from customers who defect.
Advanced stockout model
Per event + annualizedModel how customers respond to unavailable inventory
Demand & stockout event
Original item economics
Customer response to stockout
Substitute item economics
Customer & recovery costs
Advanced methodMissed demand first flows to substitutes, then backorders, then permanent lost sales. Contribution shortfall compares the contribution that would have been earned on the original demand with contribution retained through substitutes and successful backorders. Total economic cost adds backorder administration, future customer value lost, service recovery and emergency costs. Lost revenue is reported separately and is not added again to avoid double counting.
Cost bridge
Revenue is shown separately, not added to economic costWhere the stockout cost comes from
| Cost component | Per event | Share of event cost | Annualized |
|---|
Duration sensitivity
Behavior and unit economics held constantCost if the stockout lasts longer or shorter
| Stockout duration | Missed units | Permanently lost units | Revenue shortfall | Economic cost / event | Annualized cost |
|---|
Recovery sensitivity
Substitution and cancellation assumptions preservedCost as backorder recovery changes
| Backorder rate | Successful recovered units | Permanently lost units | Demand retained | Economic cost / event |
|---|
Customer-retention sensitivity
Direct sales economics held constantCost as stockouts damage customer retention
| Defection rate | Expected customers lost | Future customer value lost | Event economic cost | Annualized cost |
|---|
Scope
Stockout cost is broader than lost revenue
This calculator estimates economic exposure from the assumptions entered. Customer substitution, backorder behavior and defection are often uncertain, so sensitivity testing is important. The tool does not automatically model demand that shifts between periods, channel-specific penalties, contractual service-level penalties, marketplace ranking effects, sales-team time, production downtime or reputational spillovers. Future customer value should exclude the current lost transaction when it is added to immediate contribution loss.