The Runway Playbook A guessed runway is worse than none. Know how long you have.
Ask yourself how many months you have and the answer moves every time you press it. Gross or net? With the annual bills? Assuming the deal closes? This guide settles the definitions, builds the simplest honest model, and turns the number into decisions.
The most important number in your business is a guess.
It gets calculated occasionally, by dividing the bank balance by a rough feeling about monthly spend, and then it lives in your head for a quarter. No number makes you careful. A wrong number makes you confident, and you spend against months you do not have. The usual failure is not running out of money suddenly. It is finding out four months later than you should have, when every option left is worse.
None of them is "watch your spending".
You do not have a strategy problem, you have a sequencing problem. Runway turns vague pressure into a date, and people who know the date plan backwards from it.
If you ever need outside capital, the biggest factor is whether you can walk away. Your leverage is decided by when you start relative to your runway, and that costs nothing but knowing the number early.
Most spending is not decided, it accumulates. A live model shows the rate, and once you can see it you can steer it. It is also the fastest way to find money you already have.
Long runway permits patient bets and experiments that take two quarters to read. Short runway permits none of that. Choose the strategy that matches the clock, not your ambition.
A monthly figure is an abstraction. What a commitment really costs is months, and months make a decision clear: what does this need to produce before the clock runs out?
Churn, slow sales, a compounding cost, slipping payments: each moves the runway weeks before any other report. Look monthly and ask why it moved.
A number you can steer by.
Not a finance course. One sentence that defines your runway, a model small enough to keep current, thresholds you set while calm, and a thirty minute monthly loop that turns a spreadsheet into an early warning system.
Five parts, in order.
Six mechanisms, each of which changes a decision you are making blind, and the honest limit: runway is a forecast, and forecasts age.
Gross or net burn, cash not accounting profit, what counts as cash, the burn window, current versus planned burn, and the one sentence you quote every time.
Four inputs, categorised outflow, connected accounts, lumpy items on the calendar, income in three honest buckets, a fixed monthly refresh, then stop building.
Three thresholds set in advance, starting from the trigger and not the panic, extending runway cheapest first, pricing commitments in months, and interrogating every movement.
Build the model, set the thresholds, run the monthly review. Each line is a box you either can or cannot tick, and the one you cannot is your next task.
Nine ways businesses that had the information still ran out of time. All of them are failures of definition and timing, not of arithmetic.
I have N months, calculated on net burn over a trailing three month average, counting only cash actually in the bank, assuming the current plan. Use the same sentence every time you quote the number.
Work out runway on current burn, then on planned burn including everything you intend to commit to. The second is always shorter and always the honest one. If the two are far apart, you have a wish with a shopping list attached.
Comfortable, Act and Emergency, written down while you are calm. At the moment you cross one you will be under pressure and very good at finding a reason to wait one more month.
- You run a business on your own and want to scale it, and you want to know how long you can keep going while you do.
- You are willing to count cash, not hope, and to run the planned-burn number even though it is shorter.
- You want a model you will still maintain in six months, not an impressive one.
- You want a method with checklists, not a lecture about being careful with money.
- You want a forecast accurate to the second decimal place. The guide treats runway as a range with a direction.
- You want a five-year scenario model. The guide says to stop building until the simple one has changed a decision.
- You want tax or accounting advice for your situation.
- You expect a spreadsheet to save the business without you ever looking at it.
Every month you protect is a decision you keep.
Runway is not really about cash. It is about ownership and control. A month preserved is equity you do not have to sell and a choice you do not have to hand to someone else. Know the number. Look at it once a month. Then spend your time on the thing that gets you a customer.
Luis Gonçalves
Twenty years in digital product development. Led the agile transformation at Nokia. Teaches at Porto Business School. Has spent the last decade working with founders across Saudi Arabia, Portugal, Brazil, and the broader emerging-market startup ecosystem.
He calls himself the Dark Entrepreneur because he believes the founder world is allergic to honesty. No success theater. No highlight reels. Just the real work that has to happen.