How long does your startup survive? Enter your cash position and costs — get your runway with bear, base, and bull scenarios modeled instantly.
Burn rate is the speed at which a startup spends its cash reserves. It is one of the most watched metrics by investors and one of the most misunderstood by first-time founders. There are two versions: gross burn is total monthly cash outflow regardless of revenue; net burn is what you actually lose per month after subtracting revenue. Net burn is the number that tells you how long you survive. Knowing both — and the gap between them — reveals how dependent your runway is on revenue growth versus investor capital.
Runway is the direct consequence of burn: divide your cash balance by net monthly burn and you get the number of months until you run out of money. Most investors expect a funded startup to carry 18–24 months of runway at any given time. Below 12 months, you are already fundraising under pressure. Below 6 months, every conversation with an investor shifts from opportunity to desperation.
Single-point runway calculations are dangerous because they assume the future mirrors the present. A three-scenario model — bear, base, bull — forces you to stress-test your assumptions. The bear case models slower-than-expected revenue growth and cost overruns; this is the survival floor. The base case reflects your realistic forecast. The bull case models accelerated traction, and is useful not for planning but for understanding the upside leverage of hitting your targets early.
The scenario spread matters as much as the midpoint. A startup with a base runway of 18 months but a bear runway of 7 months is in a fundamentally different position than one where the bear case still lands at 14 months. Investors read scenario spread as a signal of operational resilience. Tight spread means predictable business. Wide spread means execution risk.
A Berlin-based SaaS startup has €380,000 in the bank after a €400k pre-seed round. Monthly costs: €18,000 salaries, €2,000 infrastructure, €3,000 marketing, €1,500 other — total gross burn of €24,500. Current MRR is €4,200. Net burn is therefore €20,300 per month.
Base case: With 8% MoM revenue growth and 3% cost growth, runway extends to approximately 17 months. Bear case (4% revenue growth, 5% cost growth): runway collapses to 11 months — a fundraising red zone. Bull case (15% MoM growth): default avoided entirely; the company reaches cash-flow breakeven before running out of capital. The base-to-bear delta of 6 months is the risk window the founding team must manage.
There is no universal answer — it depends on your market, team size, and growth rate. As a rough benchmark, seed-stage SaaS startups typically burn between €15,000 and €60,000 per month. What matters more than the absolute number is the burn multiple: how much you spend for every euro of net new ARR. A burn multiple below 1.5x is considered efficient; above 2x starts to raise investor eyebrows at the Series A.
Start fundraising no later than when you have 9–12 months of runway remaining. A typical seed or Series A round takes 3–6 months to close from first meeting to wire. Starting at 6 months leaves no margin for a slow process, investor drop-outs, or legal delays. Many experienced founders begin the process at 12–15 months remaining and treat the round as closed only when the money is in the bank.
Report both, always. Gross burn shows operational scale and cost discipline. Net burn shows survival trajectory. Investors want to see both trends over time — a declining net burn with flat gross burn means revenue growth is doing its job. A rising gross burn with flat net burn suggests costs are accelerating without proportional revenue improvement.
Start with infrastructure and tooling — these are often the easiest cuts with minimal growth impact. Audit subscriptions quarterly; SaaS tool sprawl is a common culprit. Delay hires that are not directly tied to revenue or product delivery. Move marketing spend toward organic and owned channels. The goal is not to minimize spend but to maximize revenue-per-euro-burned. A startup spending €30k per month to generate €100k in new ARR is in a better position than one spending €15k to generate €20k.