Free tool · For DTC brands on Shopify · $1M–$30M/yr

Stockout Cost Calculator

An out-of-stock isn't a $0 event — it's demand you already earned, walking out the door. Plug in your own numbers and estimate the annual revenue and gross profit your out-of-stocks are quietly costing you.

Your numbers

Adjust any field. Everything updates instantly. Nothing is sent anywhere — this runs entirely in your browser.

Units sold per day when in stock — average daily unit velocity of a SKU while it's available.

/day

Days out of stock per year — total days per year this SKU sits at zero (missed restocks, delayed POs, oversell zeroing you out).

days

SKUs affected — roughly how many SKUs go out of stock at about this frequency. Use 1 to size a single SKU.

SKUs

Selling price per unit — typical revenue per unit for these SKUs.

Gross margin — your gross profit as a % of price (price minus unit COGS).

Demand you recapture later — your estimate of the % of stockout demand that comes back as a backorder, substitute, or later purchase. The rest is gone for good. (Retail estimates often put permanent loss well above half — adjust to your business.)

Your estimate

Revenue lost for good / yr

Gross profit lost for good / yr

Based on an estimated 0 units of demand hitting an empty shelf this year.

Where your out-of-stock demand goes	Revenue / yr
Recaptured later Backorder, substitute, or a later purchase	$0
Lost for good Bought a competitor, or never came back	$0
Total demand at risk (units × price)	$0

Read this as your own estimate, not a measured fact. Every figure above is calculated only from the numbers you typed, using the simple, transparent assumptions noted on each line. Real lost demand is hard to observe precisely (you can't see the sale that never happened), and the recapture rate is a judgement call — most published retail studies suggest the majority of stockout demand is not recovered, so the default here is deliberately conservative. Treat the output as a directional sizing of the problem, not a guarantee.

Why stockouts are often a data problem, not a demand problem

Plenty of out-of-stocks aren't "we sold out faster than expected." They're silent: the shelf shows stock that isn't really there, or the reorder that should have fired never did — because a sync quietly broke between Shopify, your 3PL, and your ops.

Phantom availability — Shopify says "in stock," the 3PL is actually at zero, and orders come in you can't fulfill.
Inventory drift & oversell — counts diverge until a launch or promo zeroes you out and cancels orders.
Reorder signals that never fired — a stale sync means the low-stock trigger you rely on silently stops.
Stuck receiving — inbound stock that landed but never posted to available, so you sit "out" while it's on the shelf.

What Ops Monitor actually does about this

Ops Monitor connects to your Shopify and Stripe with read-only API keys and continuously watches for the silent failures above — inventory diverging across systems, syncs that quietly stopped, orders stuck past SLA — then alerts you by email or Slack the moment one shows up, instead of you finding out from a cancelled order.

It is read-only: it never writes to your store and never moves money. It detects and alerts — it does not prevent stockouts or guarantee anything. But catching one phantom-stockout SKU before a big promo often protects far more than the $149/month price.

See for yourself

Start monitoring in minutes with read-only keys — $149/month, self-serve, cancel anytime.

Start monitoring — $149/mo →

Not ready? Run the free, no-signup Ops Scorecard to see where your store is most exposed — or have us do a one-time $29 ops audit of your store.