Explain Cash Runway Without Hiding the Next Large Payment

A slide that says "five months of runway" is arithmetically fine. It is also, often enough, the reason a room agrees on a date that will not happen. The number divides two things that do not have the same shape: a cash balance at a moment in time, and a rate of spending measured across a period. The division assumes payments arrive like a metronome. When one payment is much larger than the regular ones, that assumption fails in the direction that flatters the company.

The repair is not to throw the average away. An average is a reasonable description of regular months, and a deck needs a short description somewhere. The repair is to keep the average, put the actual payment dates next to it, and name the event that breaks the pattern. Three things make that work: a dated cash figure, a defined burn, and a walk through the expected payments in the order they will occur.

Define the starting cash and the planning date

Cash is a fact with a timestamp. A balance without a date is not a balance; it is a memory. If the deck is presented on the twentieth of the month, the opening figure should be the most recent close you actually have, and the slide should say which close that was. A number from six weeks ago is a weaker claim than a number from Friday, and the reader deserves to know which one they are looking at.

"Available" is the second half of the definition, and it is narrower than "cash." Some money on the balance sheet is not available for the stated purpose. Deposits collected from customers for work not yet delivered. Payroll taxes withheld from employees and not yet remitted. A minimum balance a lender requires the company to keep on deposit. Whether a particular item reduces availability depends on the company and the arrangement, and the person who owns the cash forecast is the one who should define it. Ask them which amounts they treat as committed, then use their answer consistently — the definition matters less than the consistency.

Then the part that fails most often in decks: expected money is not cash. An invoice issued is not cash. A signed contract with payment terms is not cash. A term sheet is not cash. Each of these can fund payments later, and each belongs on a timeline with a date and a description of how conditional it is. None of them belongs in the opening balance merely because the plan assumes they arrive.

There is a specific double count to watch for here. If an uncollected invoice is added to the opening cash and then appears again in month four as an expected collection, it has been counted twice, and the runway is longer than either view on its own would suggest. The opening balance should contain money the company can already direct, and nothing else. Everything expecting to arrive goes on the path.

Explain what the average leaves out

Before dividing anything, define the burn. Which cash flows are inside it? Does it include one-time payments, equipment purchases, debt service, tax? Is it a gross outflow, or are collections netted against payments? Over what window was it measured — three months, six, twelve? Every one of those choices changes the answer, and each carries a different vulnerability. A twelve-month window might carry an annual insurance premium that a three-month window leaves out. A three-month window might land entirely inside a slow quarter.

For the illustration that follows, the definition is deliberately narrow. The figures are invented, and the units are arbitrary; only their relationships matter. Available cash is 100. Regular monthly outflow is 20. There are no receipts. Cash divided by the regular outflow gives five months. That reframes the arithmetic cleanly, because the 20 covers only regular payments by definition. Everything else is an exception that has to be shown separately.

What the five months does not mean is worth stating plainly on the slide or next to it. It is not a date on which the company stops operating. It is not a guarantee that it continues. It is a statement about how long the current cash covers the regular outflow, on the assumption that the regular outflow is all that happens.

One distinction underneath the burn is worth keeping visible, because it is easy to skip. Profit and cash movement are different things, and the cash-flow section of the SEC's investor education guide on financial statements — US material dated February 4, 2007 — separates them as a basic point of reading financial statements. That guide does not supply a runway formula, and the arithmetic here is not taken from it. The useful takeaway is narrower: the denominator of a runway calculation is a cash measure, not an expense measure. A prepaid annual premium leaves the bank in one month and reaches the income statement across twelve. If the burn was built from recognized expenses rather than cash movements, the timing is already wrong before any large payment shows up.

Finally, ask what is inside the 20. If the window you averaged over happened to contain a large one-time payment, the average already carries it, and putting that same payment on the timeline again counts it twice. If the window was clean, the average excludes it, and that is the opposite problem. Which problem you have depends entirely on the window. The audit question is short: what period produced this number, and what was in that period?

Put material cash events on the time path

Now the event the headline buried. A payment of 45 is due in month three. It is not part of the regular 20 — that is the whole point of it. Track the cash in order.

The baseline says the regular outflow is covered for five months. The path says a payment in month three exceeds the cash on hand at that point by 5. The 45 is worth two and a quarter regular months on its own — that is the entire reason the two views diverge this sharply, and putting the figure next to the baseline makes it legible without a paragraph of explanation.

The last cell is a shortfall, not a balance. A cash account cannot hold negative 5, and the illustration does not assume an overdraft that would let it. The slide should read: 40 available, 45 due, 5 to find. Finding it is a decision — moving a payment, delaying a purchase, collecting sooner, drawing on funds the company already has a right to — and the example does not say which. What it does say is that the five-month headline and the month-three shortfall describe different things, and only one of them is what the company will actually experience under these assumptions.

One timing detail the grid cannot resolve. Within month three, the order of the two payments changes when the balance dips, but not whether it dips: 60 covers either payment alone and not both. If the 45 is due early in the month, the gap arrives early. Daily detail is what answers that, and if the day matters to the decision, a monthly view is the wrong instrument. The grid can tell you the gap appears in month three. It cannot tell you which morning.

Notice, too, that the 45 appears exactly once. It is not inside the 20, and it is not also subtracted somewhere else. Keeping each item in one place is what makes the path trustworthy; the same discipline that keeps an uncollected invoice out of the opening cash keeps a one-time payment out of the average.

Communicate the assumption that changes the answer

Every view has a load-bearing assumption. Name it, and say what kind of thing it is.

In the main example, the assumption is the 45. If it is a committed obligation on a fixed date, the gap is a certainty, and the slide should say so. If it is a discretionary plan — a project that could be deferred, a purchase with no penalty for waiting — the gap is optional, and the slide should say that instead. Those are different sentences, and merging them into one line about "potential pressure" wastes the distinction the reader needs.

A second invented variation shows the other side. Same opening cash of 100, same regular outflow of 20, no large payment. Instead, a customer is expected to collect 45 in month four. The balances run 80, 60, 40, then 65, 45, 25, 5, with a shortfall appearing in month eight. The collection buys roughly two and a quarter months of coverage.

Here is the part worth staring at. Any receipt of 45 that lands within the first six months produces that same endpoint, because without it the cash reaches zero at the end of month five and does not go below zero until the end of month six. A collection dated in month seven or later cannot help — it arrives after the unassisted balance has already gone below zero, so it cannot cover anything before it lands. The answer does not move smoothly as the collection date slips. It holds steady, then drops off a ledge. A conditional range says that far better than a point estimate: if the collection lands in the first six months, the horizon extends into month eight; if it slips to month seven or later, the extension disappears entirely.

This is also where the labels do their work. A committed obligation and a discretionary plan are not interchangeable. A confirmed source of funds — money the company already has a contractual right to draw — is not the same as a conditional one, and neither is the same as a collection that depends on a customer accepting delivery. Conditional money belongs on the timeline with its condition stated. It does not belong in the opening balance, and it should not silently become the reason a slide shows a longer horizon than the company could survive without it.

Before any of this goes in front of a reader, the person who owns the forecast should confirm three things: which amounts they count as available, which payments are committed rather than planned, and whether a given one-time item sits inside or outside the burn definition. That is a verification step about interpretation, not a second calculation.

And the boundary should be as clear as the numbers. This explains a scenario. It is not a statement that the company is solvent or insolvent. It is not an opinion about whether the company will survive. It is not a recommendation about when to raise money, and it is not evidence that financing will arrive in time to matter.

A closing version of the slide might say: cash available at the planning date, 100. Regular outflow, 20 a month. On the regular outflow alone, five months. A payment of 45 is due in month three, which is not in the regular outflow. That produces a shortfall of 5 in month three. Whether the shortfall is a certainty or a choice depends on whether the payment can move, and whether anything else arrives first is still open.

That is a longer statement than "five months of runway." It is also one a reader can act on, argue with, and plan around. The average stays where it was. It just stops being the last word.

One last discipline for whoever builds the chart: let the visual be no more precise than the underlying timing. If the collection is expected "sometime in the second quarter," do not draw it on a specific Tuesday, and do not let a smooth line imply a schedule no one has committed to. The gap in the picture should look like a gap in the information.

Frequently asked questions

Why can five months of runway mislead when a large payment is due?

The figure divides a cash balance at one moment by an average regular outflow. That assumes payments arrive regularly. A one-time payment much larger than the regular ones can make the headline look longer than the actual cash path. The repair is to keep the average, add actual payment dates, and name the event that breaks the pattern.

What makes cash available, and can expected money count as opening cash?

Available cash is narrower than cash on the balance sheet. Customer deposits for undelivered work, withheld payroll taxes not yet remitted, and a minimum lender balance may not be available. Expected money is also not cash: an invoice issued, a signed contract with payment terms, and a term sheet belong on a timeline with their conditions, not in the opening balance.

What should be defined before dividing cash by burn?

Define the burn: which cash flows are inside it, whether one-time payments, equipment, debt service and tax are included, whether collections are netted, and the measurement window. The denominator is a cash measure, not an expense measure; a prepaid annual premium leaves the bank in one month and reaches the income statement across twelve.

What does the month-three shortfall mean in the illustration?

In the invented example, 40 is available and 45 is due, so 5 must be found. That is a shortfall, not a negative balance; the example does not assume an overdraft. Whether the gap is certain or optional depends on whether the payment is a committed fixed obligation or a discretionary plan that can move.

Why does collection timing drop off a ledge rather than move smoothly?

Without a receipt, cash reaches zero at the end of month five and does not go below zero until the end of month six. A 45 receipt in the first six months extends the horizon into month eight; a receipt in month seven or later cannot cover anything before it lands. A conditional range expresses that better than a point estimate.

Further reading

• Show Recurring and One-Time Revenue Without Calling Everything ARR — Useful when a mixed invoice must be split: it applies the same discipline to revenue, keeping one-time work out of the committed recurring figure.