How much are stock mistakes costing you each month?
Quick estimate of money lost to stock errors: cancellations, refunds, and customers who never return.
Your numbers
Fits hobbyists & side hustles
- Refund rate on problem orders 75%
- Support & handling per issue $8.00
- Future revenue impact factor 15%
Move the sliders to see
how much this is costing you
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The hidden cost of overselling
Inventory mismatches rarely show up as a single metric — they leak through refunds, support load, and lost repeat purchases.
Teams optimize traffic, CAC, ROAS, and conversion, while a quieter number drains margin in the background: the cost of inventory drift. An oversell is rarely “just a refund” — it usually triggers a chain reaction across systems.
This calculator is a visibility tool: it models the most common places oversell damage hides so you can estimate the monthly impact.
Assumptions (benchmarks, not accounting precision): ~75% refund rate, $8 support handling cost, ~15% future impact factor. Use this to make an invisible category of loss visible — then refine with your internal data.