How much are stockouts actually costing you?
Plug in your own numbers and see a rough monthly cost, with the math shown right on the page. No email required to see your result.
Your numbers
Defaults are filled in with typical small-store figures so you can see how it works. Swap in your own and the result updates live.
This is our own illustrative model, not an audited industry formula. Every store's mix of demand, margin, and traffic is different, so treat this as a starting estimate, not a forecast.
How we calculate this
The formula behind the number above, in plain terms:
Monthly revenue lost = Visitors x Conversion rate x AOV x % catalog out of stock
Visitors, conversion rate, and average order value give you your store's normal monthly revenue. We scale that number down by the percent of your catalog that's out of stock at any given time, which is our stand-in for how much of that demand hits a dead product page instead of a checkout.
Average days until restock isn't part of the multiplication. It's context: a shorter restock window means less of the month spent in that exposed state, a longer one means more. We'd rather show you a simple, honest formula than dress up a fake decimal of precision with a variable that doesn't actually change the math.
The caveat, stated plainly: this is an estimate, built on a straightforward illustrative model, not a scientific study of your store. Real stockout cost depends on which SKUs go out (your bestsellers hurt more than your long tail), whether customers substitute another product instead of leaving, and plenty else this calculator can't see. Use it as a gut check, not a guarantee.
Stores typically recover a slice of this, not all of it
We're not going to invent a recovery percentage here. How much of that lost revenue comes back depends on your waitlist size and how reliably your restock emails actually get delivered and opened. What we can tell you: a customer who signed up to be notified is a customer who already wanted to buy. Kelso emails them the moment you're back in stock, so you're not counting on them to come check again on their own.
The first 50 stores lock today's price for as long as they stay subscribed. Joining the waitlist holds your spot.
Questions about the math
How is this calculated?
Monthly lost revenue = monthly store visitors x conversion rate x average order value x percent of catalog out of stock. That last number is what scales everything down to just the demand that hits a dead product page. It is our own illustrative model, not an industry-audited formula, and every store is different.
Why does average days to restock not multiply into the total?
It is context, not a multiplier. The estimate above is a monthly snapshot. A longer restock window means that snapshot repeats for more of the month, and a shorter one means less of it does. We show the number so you can judge your own exposure, but we would rather be honest about the model than dress up a fake precision.
Will a back in stock app recover all of this?
No, and anyone who tells you a fixed percentage is guessing. Recovery depends on your waitlist size and how reliably those emails actually get delivered and opened. Some of it comes back, not all of it, and we are not going to invent a number to make the tool look more impressive.
What counts as "out of stock" in this calculator?
Any product or variant a customer could want that shows unavailable when they land on it, whether that is a whole product or just their size or color. The percent of catalog out of stock field is your estimate of how much of your total demand hits that wall at any given time.