Runway

Runway is how long your business can keep operating before it runs out of money: your cash balance divided by your net monthly burn. If you hold £30,000 and lose £5,000 a month, you have six months of runway. It's the single number that tells you how much time you have to make the business work.

For a lean founder, runway is the clock behind every decision. It dictates how bold you can be, when you must reach profitability, and how long you can survive a slow start. A short runway forces ruthless prioritisation; a long one buys room to experiment. Crucially, runway extends two ways: by raising or saving cash, but also by growing revenue so your net burn shrinks toward zero.

The discipline is watching it honestly and acting early. Say you're running your books in Moneybird: your cash position and monthly outflow are already sitting there, so runway stops being a guess and becomes a live figure you can read off the ledger. Then look at where the burn actually goes. Say you're paying for HubSpot seats you've outgrown, or a Webflow plan that's heavier than the site you ship, every recurring tool is a slice of the burn, and trimming a few of them can add a month or two of runway without touching revenue at all.

Founders who track runway loosely tend to wake up to a crisis; those who watch it weekly adjust spending, pricing or pace while they still have options. Know your number, and never let it surprise you.