Free calculator
Stockout Cost Calculator: Lost Revenue From Being Out of Stock
Enter how fast the product sells, what it sells for, and how long it's been (or will be) out of stock. The calculator estimates the revenue and profit the gap costs you.
Lost revenue
$1,944
44 sales missed over 12 days, after assuming 60% of demand doesn't wait for the restock.
Lost profit
$1,069
The direct hit only. Stockouts also reset ad learning, drop your search ranking and send repeat customers somewhere new — costs that outlast the restock.
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Not every lost sale is lost
Some buyers wait for the restock; many don't — they buy elsewhere or lose interest, especially for commodity and gift purchases. That's the “sales lost for good” slider. Loyal-customer, differentiated products can set it low; interchangeable products belong near the top.
The costs the formula can't see
A stockout also pauses your ad campaigns' learning, drops your search and marketplace ranking, and hands repeat customers a reason to try a competitor. Those compounding effects are why chronic stockouts cost more than this one-off estimate — and why the fix is a reorder point, not a bigger panic order.
Full walkthrough: Overstock vs stockout: which costs more?.
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Frequently asked questions
How do I calculate the cost of a stockout?
Multiply average daily sales by the days out of stock to get missed demand, discount it by the share of buyers who genuinely won't wait, then value it at your price for lost revenue and at your margin for lost profit. This calculator does exactly that — the honest uncertainty is in the won't-wait share.
What percentage of sales are lost permanently during a stockout?
There's no single number — it depends on how replaceable your product is and how loyal the buyer. For commodity items most unmet demand goes to a competitor immediately; for differentiated products with repeat customers, more of it waits. Bracket it: run the calculator at a low and a high share and treat the range as the answer.
Does going out of stock hurt my ranking?
It can. Marketplaces demote or hide unavailable listings, ad campaigns stop spending and lose their optimization history, and on your own store an out-of-stock page converts traffic you already paid for at zero. Recovery after restock isn't instant, which adds an invisible tail to the cost.
How do I prevent stockouts without overbuying?
Set a reorder point — average daily sales × supplier lead time, plus safety stock — per product, and recalculate it when sales speed or lead times change. Safety stock sized to your worst realistic case absorbs spikes; the reorder point makes sure the order goes out while there's still runway.