Will your startup survive? Runway, burn & default-alive — one page
Three numbers decide whether your project reaches profit before it runs out of money: runway (how long the cash lasts), burn (how fast you lose it), and whether you’re default-alive (on track to profit before zero). Here they are on one page — with the ranges that actually matter, and the source for each.
No invented benchmarks: cited ranges where they exist, and your own numbers where they don’t.
① Runway — how long your money lasts
Runway = cash ÷ monthly net burn.
Net burn = what you spend minus what you earn each month.
There’s no universal “right” number — it depends on your plan and how fast revenue is ramping. So we won’t hand you a made-up benchmark: the free calculator computes YOUR runway, your zero-cash month, and whether you break even first.
② Burn — how fast, and how efficiently
Net burn is the raw speed. The burn multiple (only if you have recurring revenue) = net burn ÷ new recurring revenue — dollars burned per $1 of new revenue. The rule: above 3 is “suspect or bad.” A business that just started selling can sit at 3; it should improve as you grow. (David Sacks, “The Burn Multiple,” Craft Ventures, 2020.)
③ Default-alive — the one question
Are you on track to reach profitability before your cash hits zero, at your current growth and spending? Yes → default-alive (you can survive without raising more). No → default-dead (at current trends you run out first).
Paul Graham’s point: half the founders he talks to don’t know which they are — and you reach the fatal pinch by not noticing you’re heading there.
④ The reference ranges that actually matter
Healthy ranges distilled from published research, read by stage and business type. Context, not a pass/fail — your situation sets what’s right. They kick in once you have paying customers.
| Number | What it means | Healthy | Source |
|---|---|---|---|
| LTV : CAC | A customer’s lifetime value vs what it costs to get one | ≥ 3 (flag under 1.5) | David Skok |
| CAC payback | Months to earn back what you spent acquiring a customer | ≤ 18 months (early stage) | David Skok |
| Gross margin | Revenue left after the direct cost of delivering it | 75–85% for software | Benchmarkit 2025 |
Gross margin varies by your business model.
If your business is subscription:
| Monthly churn | Share of customers who cancel each month | 3,5–6% (low price points) | ChartMogul 2024 |
⑤ Check your own numbers
This page is the map — your real numbers are what matter. The free viability calculator turns your cash, burn, revenue and growth into your runway, your break-even month and a default-alive verdict, in minutes.
Try the free calculator →How we calculate →
FAQ
What's a healthy runway?
No fixed number — it depends on your plan and revenue ramp. Compute yours with the free calculator.
What does default-alive mean?
You're on track to reach profit before your cash runs out, at current trends (Paul Graham).
Where do these numbers come from?
A benchmark box that cites the source, year and measured population for each — not a generic list. See the methodology.
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Last updated: June 25, 2026. For information only — not financial advice.