A profitable company can fail by growing

It is the sentence every entrepreneur has heard and nobody really believes, until it happens to them. The income statement is solid, every order carries a good margin, the order book is full, and the bank calls to say the account is overdrawn.

It is not a paradox, and it is entirely ordinary. When revenue grows, so does the money locked inside the operating cycle: goods to be bought before they are sold, inventory to keep stocked, customers paying at ninety days. That growth in working capital must be financed today, while the margin that repays it arrives later.

The phenomenon has a name, overtrading, and a rule: there exists a growth rate beyond which a company, however profitable, cannot go under its own power. This calculator determines it.

The limit is not the margin, it is the cycle

Common intuition says a firm can grow as fast as its profitability allows. That is only half true, and the missing half is the one that causes default.

Call the cash cycle the number of days between the moment you pay and the moment you collect: days of inventory, plus days of customer credit, minus days of credit your suppliers grant you. It is the time your money spends outside, at work, but not yours.

Every unit of additional revenue requires advancing a fraction of itself for the duration of the cycle. If the cycle is 120 days and what you sell costs 82% of its price, every unit of growth ties up about 27 cents. Not once: for as long as the growth continues.

Hence the formula. The cash operations generate in a year is the cash margin minus the fixed cash costs. The cash growth absorbs is proportional to the growth rate, to the cycle, and to what your sales cost you. The self-financeable growth rate is the one at which the two quantities are equal. Above it you need someone else's money; below it, you accumulate your own.

Identical income statement, opposite fates

The most useful thing this model shows is that two firms with the same accounts can have growth limits differing by a factor of sixteen.

The table takes a single company — five million in revenue, an 18% cash margin, 600,000 of fixed costs — and changes only the cycle. The income statement is identical in every row. Profit, margin, costs: all the same. Only the days between paying and collecting change.

The first row and the last are the same company. The first can grow 178% a year without asking anybody for anything. The last strains already at 11%, and at 25% growth — which any board would celebrate — must find outside two and a quarter times the cash it produces.

No profitability indicator tells these five rows apart. The income statement is silent about the risk that separates them, because the risk does not live there: it lives in time.

How this calculator works

Five values are needed, and none depends on currency: enter the amounts in yours and read the results in the same one.

Annual revenue is the starting point. The cash margin is the percentage of revenue left after variable cash costs: purchases, materials, commissions, subcontracting. It is not the accounting gross margin, because it excludes depreciation and other items that move no money.

Fixed cash costs are the recurring outflows that do not follow volume: structural salaries, rent, subscriptions. Here too, only what genuinely leaves the bank.

The cash cycle is days of inventory plus days of customer collection minus days of supplier payment. It is the most important number on this page, and almost nobody tracks it monthly. Expected growth is growth in revenue, not in orders.

How to read the results

Cash absorbed by growth is how much money the expansion will ask of you this year. Cash generated by operations is how much you produce: cash margin minus fixed cash costs.

Self-financeable growth is the percentage beyond which the two swap places. It is a number worth pinning to the office wall, because it bounds the only growth that does not require a call to a bank, a partner or a fund.

Cash strain is the verdict metric, and it is dimensionless: the ratio of cash absorbed to cash generated. Below 0.5 growth is comfortably self-financed. Between 0.5 and 1 it still is, but the cushion is thinning. Between 1 and 1.5 you are growing beyond your means: every new order, however profitable, takes liquidity away from you. Above 1.5 it is overtrading, and this is how profitable companies fail.

Why every new order can drain your liquidity

The most counterintuitive claim in the verdict deserves a pause, because it is the one no salesperson accepts.

A profitable order generates margin. But it generates it afterwards: after you bought the raw material, after you processed it, after the customer paid at ninety days. Meanwhile the order has absorbed cash equal to its entire variable cost, for the whole length of the cycle.

If the cash margin is 18% and the cycle 120 days, every unit of additional order gives back 18 cents many months later and demands 27 right now. In a snapshot the order is nine cents underwater, and stays there for as long as the firm keeps growing at the same pace. Only when growth stops does working capital stop rising and the margin surface all at once.

Hence the hardest fact to swallow: an overtrading firm improves its cash by slowing down, not by accelerating. This is not prudent advice, it is arithmetic. And it explains why so many companies discover liquidity precisely in the year revenue stops running.

How this differs from the classic sustainable growth rate

If you have used the return on equity calculator, you will have seen among its outputs a sustainable growth rate: ROE multiplied by the retained share of earnings. It is a useful quantity and it answers a different question from ours.

That formula is accounting: it says how fast equity can grow if the company reinvests its profits and holds leverage constant. It reasons on an accruals basis, not in cash, and nowhere does it contain the time between paying and collecting.

The self-financeable growth on this page is cash. It can be far below the accounting rate for a firm with a long cycle, and far above it for one that collects quickly. A company can post excellent profits and have a 5% self-financeable growth; another can post modest profits and grow 100% without asking for anything. The first fails, the second does not, and neither of them sees it by looking at ROE.

The three levers, and which one to pull

The self-financeable rate depends on three things: how much cash you generate, what your sales cost you, and how many days the cycle lasts. So there are three levers, and they do not cost the same.

Raising the cash margin is the most powerful lever, because it acts twice: it raises the cash generated and lowers the share of revenue to be advanced. At the reference values, one extra point of margin is worth about twenty days off the cycle. It is also the hardest lever: were it easy, you would have pulled it already.

Shortening the cycle is nearly always the underused lever, and it breaks into three: collect sooner, turn inventory faster, pay suppliers later. None requires selling more or producing better; they require administrative attention, which costs little and is almost never given.

Cutting fixed cash costs raises the cash generated but does not touch the requirement per point of growth. It is the lever everyone talks about and the least effective on the growth rate, however useful elsewhere. For a static picture of your liquidity, the working capital calculator remains the right tool; this page measures instead its derivative: how much working capital next year's growth will ask of you.

Limits of the estimate

This tool is a simplified model for educational purposes, not financial advice. It assumes the cash cycle and the margin stay constant while growing, whereas in reality growing fast worsens both: terms get conceded to win orders, more inventory gets held to serve new volumes, less efficient batches get bought.

It assumes revenue grows evenly, whereas seasonality can burst the cash in one month and leave it abundant in another: the annual rate may be sustainable while the peak is not. It does not model capacity investment, which adds to the working capital requirement and often exceeds it.

It does not model financial structure: an invoice facility, an advance against contracts, an equity round all move the constraint without changing the arithmetic. Use it to know your rate and how far short you would fall at the pace you have in mind; for the treasury plan, consult a professional.

Frequently asked questions

What is self-financeable growth?

It is the maximum revenue growth rate a company can sustain on the cash its own operations generate, without debt or outside capital. It depends on the cash margin, the fixed costs, and above all on the length of the cash cycle.

How is it calculated?

Cash generated = revenue × cash margin − fixed cash costs. Cash absorbed per point of growth = revenue × (cycle ÷ 365) × (1 − cash margin). Self-financeable growth is the ratio of the two, as a percentage. Cash strain is the cash absorbed by expected growth divided by the cash generated.

How can a profitable company fail?

Because profit is accrual and cash is time. Growing, the company must advance the variable costs of every new order for the whole length of the cycle, while the margin comes back much later. If the cycle is long, the advance exceeds cash generation and outside money is needed to stay upright.

What is the cash cycle?

Days of inventory plus days of customer collection minus days of supplier payment. It is the time your money has left your account and has not yet come back. The longer it is, the more working capital each point of growth requires.

What does a cash strain of 1.5 mean?

That expected growth absorbs one and a half times the cash operations generate. Half of what the expansion requires must be found elsewhere: bank, shareholders, extended terms. Above 1.5 the model classifies the situation as overtrading.

Why is margin a more powerful lever than the cycle?

Because it acts twice: it raises the cash generated and lowers the share of revenue to be advanced. At the reference values, one extra point of cash margin equals roughly twenty days off the cycle. It is, however, the hardest lever to pull.

What if the cash cycle is negative?

Then you collect before you pay, and growth generates cash instead of absorbing it: there is no self-financing limit to compute. This is the case for many retailers, marketplaces and prepaid subscriptions, and it is why they can grow at rates that would default a manufacturer.

How does this differ from the classic sustainable growth rate?

The classic rate is ROE times the retained share of earnings: it is an accounting figure and ignores the time between paying and collecting. This page's rate is a cash figure and depends on the cycle. A company can post an excellent ROE and have 5% self-financeable growth.

Does the calculator work in any currency?

Yes. Amounts are treated as pure numbers: revenue, costs and results come out in the input currency. Self-financeable growth and cash strain are pure, dimensionless ratios, and they do not change if you multiply revenue and fixed costs by the same constant.

Why does slowing down improve cash?

Because the working capital requirement is proportional to growth, not to the level of revenue. If growth stops, working capital stops rising and the margin, which keeps accruing, finally turns into cash. It is why many firms become liquid precisely in the year they stop growing.

What is not included in the model?

Capacity investment, intra-year seasonality, the worsening of cycle and margin caused by growth itself, and financial structure. An invoice facility or an equity round move the constraint, but they do not change the arithmetic that produces it.

Does this tool replace a treasury plan?

No. It is an annual, even-paced model, whereas cash breaks at monthly peaks. Use it to know your rate, how far short you would fall at the pace you have in mind, and which lever to pull; for the plan, consult a professional.

The three levers, side by side

Knowing the limit exists helps little if you do not know which dial to turn. The table takes the reference case — a self-financeable growth rate of 22.26% — and applies five realistic interventions, one at a time.

The instructive comparison is between the fourth row and the first three. One point of margin is worth about twenty days of cycle — as much as all three working-capital interventions combined. Margin is the strongest lever because it enters the formula twice: it increases the cash you generate and reduces the share of revenue you must fund up front.

But the column that decides is the last one. Raising prices by a point without losing volume is a year-long project; sending reminders ten days earlier is a week-long one. The three cycle levers, added together, are worth almost ten points of self-financeable growth and require neither selling more nor producing better: they require someone to look at the numbers on Monday morning.

This is why firms that survive their own growth almost never do it through a commercial miracle. They do it because they stopped treating the back office as a cost centre.

The cash deficit, one growth point at a time

The next table shows the same company accelerating. Revenue five million, cash margin 18%, fixed cash costs 600,000, cycle 120 days: cash generated stays at 300,000 in every row, because growth does not change it. Only the requirement changes.

The middle row is the break-even: at 22.26% the balance is exactly zero, not by construction of the table but by definition of self-financeable growth. Above that threshold the balance turns negative with perfect linearity: every extra five points of growth cost roughly 67,400 of cash that somebody else must lend you.

Note there is nothing dramatic about the crossing. There is no threshold beyond which the company «breaks»: there is only a number that turns negative, and that nobody watches because the income statement keeps improving. Between 20% and 25% growth, profit rises and cash collapses simultaneously, and the two facts are read by two different people in two different meetings.

The 40% row is the one that produces defaults: the company grows splendidly, the board is delighted, and 239,000 a year is needed that exists nowhere except in a credit line which, sooner or later, will not be renewed.

When the cycle is negative: growing while generating cash

The calculator rejects a zero or negative cycle, and that is not a limitation of the model: it is its most interesting conclusion.

If you collect before you pay — the annual subscription billed upfront, the supermarket that sells today and pays in ninety days, the marketplace that holds the money until delivery — then every unit of growth does not absorb cash: it generates it. No maximum self-financeable rate exists, because growth funds itself and usually funds something else too.

This is the structural, not ideological, reason certain business models grow at rates that would bankrupt a good manufacturer. They do not have better margins: they have the sign of the cycle reversed. A firm with a 4% margin and a negative cycle can grow 60% a year on its own cash; one with a 20% margin and a hundred-and-twenty-day cycle stops at 22%.

From which follows an observation worth more than many strategies: the cash cycle is a business-model variable, not merely an administrative one. Asking for a deposit at signature, selling by subscription rather than by consumption, pushing inventory onto the supplier are not accounting adjustments. They are ways of flipping the sign of the inequality, and therefore of buying growth that no bank would sell you at the same price.

How to shorten the cycle without losing customers

The immediate objection to any working-capital intervention is that the market will not allow it: customers demand ninety days, suppliers want thirty, inventory exists to serve. That is partly true, and the part that is not true is where the money is.

On customers, the first gain comes not from renegotiating terms but from enforcing them. In many firms average collection days exceed contractual days by twenty or thirty, and the difference is pure administrative friction: invoices issued late, orders that do not match delivery notes, nobody phoning the day after the due date. Recovering those days costs no commercial concession; it costs a process.

On suppliers, the lever is not paying late — which destroys relationships and usually costs more than it yields — but negotiating longer terms in exchange for something the supplier needs: guaranteed volumes, reliable forecasts, scheduled orders. It is a trade, not a theft.

On inventory, most of the tied-up capital sits in a minority of SKUs nobody has looked at in years. Before optimising forecasts it pays to count what you have and ask why. Average turnover lies; per-SKU turnover does not. To see which link of the chain weighs most, the cash conversion cycle calculator splits the three terms and shows which one is eating your days.

How to build a growth plan that holds

A budget that does not contain this calculation is a wish list. With it in hand, the order of construction changes.

The first step is to compute your rate before setting the revenue target, not after. If the self-financeable rate is 22% and the sales director proposes 35%, the plan already contains, implicitly, a funding request that nobody wrote down. Better to write it down.

The second is to decide consciously where the difference comes from. There are four sources and only four: slow down to your own rate, raise the rate by pulling the levers, fund the gap with debt or equity, or grow selectively, taking the short-cycle orders and leaving the long-cycle ones to competitors. The last is the least practised and often the most profitable: not all customers have the same cycle, and some are worth less than the margin they promise.

The third is to monitor cash strain as often as you monitor revenue. It is a dimensionless ratio, requires no consolidation, and updates from four numbers. A firm that knows it sits at 1.2× acts; a firm that discovers it when the bank calls does not.

The fourth, and hardest, is accepting that refused growth may be worth more than accepted growth. If customer concentration compounds the problem — a few large accounts dictating payment terms — it is worth measuring from that side too with the customer concentration calculator.

Mistakes that blow up the cash balance

The first is using accounting gross margin instead of cash margin. The former includes depreciation and provisions, which never leave the bank account; using it inflates cash generated and pushes the self-financeable rate upward — precisely in the comforting direction.

The second is reasoning on the annual average cycle when the business is seasonal. Cash need does not arrive on average: it arrives at the peak, and a growth rate sustainable over a year can be entirely unsustainable in March. The average is the body temperature of a man with his head in the oven and his feet in ice.

The third is forgetting that growth degrades the model's own variables. To win new orders you grant longer terms; to serve new volumes you hold more stock; to run faster you buy less efficient batches. The rate computed with today's parameters is therefore optimistic about tomorrow's growth, and should be used as a ceiling, not as a target.

The fourth is mistaking a credit line for a solution. A line moves the constraint by a year; the arithmetic remains. If the self-financeable rate is half of growth, the gap reappears every twelve months and grows with revenue. The bank funds a delay, not a model: and you call it in to decide precisely when you have made it indispensable.

Updated July 2026