Start with the gap between the two runways. Simple runway holds today's burn constant; runway with growth accounts for burn shrinking as revenue rises. If the gap is large, your survival depends on growth continuing. If growth slows, the timeline slides back toward the simple number.

The real question isn't how many months you have left. It's whether you reach profitability before the money runs out. Paul Graham calls this default alive: if expenses stay flat and revenue keeps growing at the rate of the last several months, do you make it on the cash you have? This tool also takes expense growth as an input, so reflect your hiring plan if you have one.

If you're default dead, there are three levers: grow faster, cut costs, or raise enough to cover the gap. "Required monthly growth" shows how hard the first lever is. "Funding gap to break-even" sizes the third. If that number doesn't fit a realistic round, talking about costs now is far cheaper than talking about them in six months.

If you're default alive, look at the lowest cash point. If cash dips very low before you reach profit, the plan has no margin for error; two bad months can put you on the wrong side of the line. Try lowering the growth assumption by a point or two and watch how the answer changes.

Finally, keep the inputs honest. Use the average of the last few months as your growth rate, not one great month. Strip out one-off revenue and late payments. The math is only as good as the inputs; optimistic inputs give optimistic answers.