The runway math founders avoid until it's too late

The clock you don't want to look at

Runway — how many months of cash you have left at your current burn — is the single number that governs every other decision. Founders avoid calculating it honestly because the answer is often uncomfortable. But not looking doesn't slow the clock; it just means you'll be surprised by it.

Do it plainly

Take your cash, divide by your real monthly burn — including the costs founders conveniently forget — and that's your runway in months. Then ask what has to be true before it runs out: what milestone, what revenue, what raise. If the milestone you need is further away than the runway you have, that gap is the most important fact about your business, and every spending decision should be measured against it.

Let runway shape the plan

Runway turns abstract advice concrete. A move that's sound with two years of cash is reckless with four months. A test that needs six months to show signal is a luxury you may not have. Good advice fits the plan to the runway — and flags when a plan quietly assumes more time or money than you actually have. Generic AI won't do that math for you. Do it yourself, and revisit it monthly.