Retention Leak Calculator
Most of your customers bought once. Here's what that's worth.
Three numbers you already know, and the arithmetic almost nobody runs. It all happens in your browser. Nothing is stored, nothing is sent, there's no email gate, and I never see what you type.
Your three numbers
People who placed their first order with you in the last 12 months. A round number is fine — this is a size, not an audit.
What a typical order is worth. If you're between two numbers, use the lower one and everything below stays honest.
Of those first-time customers, the share who ever came back for a second order. If you don't know it, put in what you'd defend in a meeting.
Your numbers
One year of first-time customers, at today's order value. Rounded to whole dollars.
Put in three numbers. The math is at the bottom of the page, so you can check my work.
You are never winning all of this back. Nobody does, and any calculator that implies otherwise is selling you something. This isn't a forecast and it isn't a target. It's the size of the pile — the one number that tells you whether the second order deserves a quarter of your year or a line in someone's status update. Most brands have never sized it, which is why it stays on the floor.
Rounded to whole people.
Nothing is stored and nothing is sent. The math runs in your browser. There's no form, no tracking on your inputs, no email gate, and no version of this where I see your numbers. Close the tab and they're gone.
Where I'd look first
Three places the second order is won or lost
The numbers above are the size of the problem. These are the three places I'd go find it, in this order, in your account. If you only get to one, get to the first.
The 30 days after checkout
Pull every customer who ordered twice and chart the gap between order one and order two. You'll see a cluster, then a long flat tail. Everything before the cluster is winnable with a nudge. Everything after it is a different and more expensive problem. Then look at what you actually send inside that window. If it's a receipt, a review request and whatever campaign happened to go out, you have a gap, not a program.
Where your email actually lands
Open a clean Gmail account, buy something, and watch where the receipt and the follow-up land. Promotions isn't broken deliverability — it's placement, and it decides whether that first window ever gets used. Check whether transactional mail and campaigns leave from the same sending domain. Then check whether people who have never once opened are still getting the same volume as people who open everything.
Who the one-timers actually are
One-and-done isn't one group. Split it by first product, by acquisition source, and by whether a discount was used. Some of those cohorts were never coming back — a gift buyer, a bargain hunter you rented for a day. Others bought the exact product your best customers start with, and then heard nothing from you. Only the second group is a retention problem. Build for that one.
The math, so you can poke at it
That's it. Every number on this page is your own arithmetic. There is no benchmark in here, no industry average, and nothing of mine baked into it. If you think the model is wrong, it's four lines of multiplication — argue with it.
Built by Andrew Lauchner, who does lifecycle and retention for consumer brands. Nothing on this page is stored or sent.