A store can be profitable on paper and still run out of cash — a restock at the wrong time, a slow month, a frozen payout. Type your numbers below and see your real cash runway, plus the traps that quietly make the number lie.
Seeded with a real example — change anything. Nothing is sent anywhere; it all runs in your browser.
Trap: if you never set "cost per item" in Shopify, your margin is a guess — and Shopify keeps no cost history, so a price change can silently rewrite last month. Stamp every cost with a date.
Trap: use what you pay the carrier, not what the customer pays you for shipping. They're different numbers and only one is a cost.
This is an estimate to show the idea, not bookkeeping. It assumes a steady month; real stores are lumpy. The point isn't the exact day — it's whether you're closer to "fine" or "act now."
Every one of these has bankrupted a profitable store. They're the difference between a number that comforts you and a number you can trust.
Your P&L can say "+$3,000 this month" while your bank account is heading to zero. Profit counts a sale the day it happens; cash counts when money actually moves — and big outflows like restocks never touch the profit line at all.
Do this: track a cash runway, not just a profit number. They answer different questions — "am I making money?" vs "am I going to be okay?"
A $15k restock doesn't show up as a $15k expense — it shows up as inventory you own. Your profit looks unchanged, but $15k just left your bank on a single day. That timing is how a growing store strangles itself.
Do this: put every known PO on a cash calendar with its date. A drop you can see coming is a problem you can move money for.
The money from today's orders isn't in your bank today — Shopify/Stripe pay out on a 1–3 day lag, and a hold can stretch that to weeks. If you run runway off "revenue," you're counting dollars you can't spend yet.
Do this: anchor runway to actual deposits (payouts), and watch how much is still "in transit" — that's the cash most at risk if a freeze hits.
Two costs founders quietly omit: their own salary (so "profit" is really your unpaid wage), and the full ad bill (counting only platform-"attributed" spend hides thousands). Both make a struggling store look healthy.
Do this: put owner pay in as a real line, and use your total Meta/Google spend, not the attributed slice.
When your supplier raises a price, most tools overwrite the old cost everywhere — silently rewriting last month's profit and breaking your history. A money tool you can't trust over time is one you'll stop opening.
Do this: effective-date every cost change, so today's price never edits the past. And show a confidence level — an honest estimate beats a fake-precise number.
"Days until $0" is the wrong line — by the time you hit zero you've already missed payroll or a supplier. The number that matters is days until you breach the cushion you swore you'd never touch.
Do this: set a buffer (1 month of overhead is a sane start) and measure runway to the buffer. That's your real deadline to act.
The calculator is a snapshot you have to come back to. Profit Gauge is a small dial that sits on your desk, keeps your runway current from Shopify, and taps you when a payout freeze or cash shock is forming — days before it lands. No bank login; you type your cash, it reads Shopify read-only.