The numbers you carry in your head are the ones that run the business.

Try this test on yourself: is your business healthy right now — not last quarter, not according to the accountant's summary, but today? Most founders can answer instantly for exactly one number: revenue. It is the number everyone asks about, the number that arrives daily, the number that feels like the score. And it tells you almost nothing about health. It tells you the business is busy.

The numbers you can say without opening a file are the numbers you actually run by. That is the whole argument for knowing a small set of them cold — not because memorising figures is virtuous, but because numbers you have to look up are numbers you react to too late.

Revenue and the bank balance are not health

The two numbers most founders carry — this month's sales and the current bank balance — are both real, and both misleading. Revenue ignores cost. The balance ignores timing: it reflects what has landed, not what is owed, committed, or about to leave. A business can post record revenue and a healthy balance while its margin quietly compresses underneath. It happens constantly, and it is invisible until it is not.

Health lives in a different set of numbers — the ones that describe the structure, not the activity.

The set worth memorising

Blended gross margin

Not the margin on the offer you are proudest of — the margin across everything you sell, after every direct cost. Blended margin answers the only question that matters about growth: does selling more actually keep more? A thin blended margin means growth buys work, not profit.

Monthly break-even

The revenue the business needs each month to cover its fixed costs — not to profit, just to not bleed. Knowing it changes how a month feels: you know when you cross the line into safety, and you know exactly how thin the pipeline can get before it becomes dangerous.

The designed profit target

The number most businesses do not have: the profit the business is committed to producing, decided before expenses are sized — the Protected Profit number. Without it, profit is whatever happened and there is nothing to measure against. With it, every month has a target and every variance has a question attached.

Cash runway

If revenue stopped tomorrow, how many months could the business operate? Runway is not about pessimism; it is about knowing how much room you have to make calm decisions. A business with three months of runway decides differently from one with nine — and should.

Revenue tells you how busy you are. Margin tells you whether the busy is worth it.

Why these and not the other forty

You can instrument a business into a wall of metrics, and many do. Most of those numbers are diagnostic — they explain what happened. The set above is directional — it tells you what to do. Margin says whether to sell more or fix the model. Break-even says whether you are safe. The profit target says whether you are on course. Runway says how much time you have to correct.

Directional numbers are also why the Command Center exists in the Alt journey — not as a dashboard for its own sake, but as the place where these numbers are live, calibrated to the profit targets set in diagnosis, instead of reconstructed at month-end when the decisions are already made.

Start with whichever number you are closest to knowing and commit it to memory this week. Then the next. A business you can describe without opening a file is a business you are actually running.