Runway Calculator
How Long Will Your Startup Survive?

Runway is the number of months your startup can continue operating before it runs out of cash. For SaaS companies, it is arguably the single most important number on your dashboard. It determines how much time you have to achieve product-market fit, close your first paying customers, and ultimately reach profitability or raise your next round of funding.

How to Calculate Runway (The Right Way)

The basic formula most people use is: Runway = Cash Balance ÷ Monthly Net Burn Rate. Net burn rate equals your total monthly expenses minus your monthly revenue. For example, a startup with $300,000 in the bank spending $30,000 per month with $5,000 MRR has a net burn of $25,000 and roughly 12 months of runway.

But this static formula is misleading for any growing company. In reality, your MRR increases every month as new customers sign up, while your expenses also grow as you hire team members, scale infrastructure, and invest in marketing. Our calculator models both growth curves simultaneously to give you a month-by-month projection — far more accurate than a single number.

Why Runway Matters More Than Revenue

Revenue is a vanity metric without context. A company doing $50K MRR sounds impressive until you learn they burn $80K per month and have three months of cash left. Runway gives you the full picture. It answers the question every founder, investor, and board member actually cares about: how much time do we have?

Y Combinator data shows that startups with 18+ months of runway are 2.3x more likely to raise a successful Series A compared to those with less than 12 months. The reason is straightforward: more runway means more experiments, more pivots, and better negotiating position when fundraising.

Three Levers to Extend Your Runway

Every founder has three options: cut expenses (reduce team size, switch to cheaper tools, negotiate vendor contracts), grow revenue faster (raise prices, improve conversion rates, reduce churn), or raise capital (angel investors, VCs, revenue-based financing). The best founders work on all three simultaneously and use scenario modeling to predict outcomes before making decisions.

When to Start Fundraising

Start fundraising when you have 6 to 9 months of runway remaining. A typical fundraise takes 3 to 6 months from first pitch to money in the bank. Waiting until you have fewer than 3 months of runway puts you in a weak negotiating position and often results in unfavorable terms, heavy dilution, or bridge rounds that do not solve the underlying problem.

Use our Break-Even Calculator to determine when your revenue will cover expenses — if break-even arrives before your runway expires, you may not need to raise at all.

Burn Rate Benchmarks for SaaS

Pre-revenue startups typically burn $5,000 to $15,000 per month. Post-seed companies burn $20,000 to $50,000. Series A companies often burn $60,000 to $200,000 per month as they scale sales and engineering. The danger zone is when burn accelerates faster than revenue growth — a pattern called burn multiple exceeding 2x. If you spend $2 for every $1 of new ARR, your capital efficiency is poor and investors will notice.

How Often Should You Check Your Runway?

Monthly at minimum. Many disciplined founders review their cash position weekly. The best practice is to update this calculator with your actual numbers on the first of every month. Compare your projections against what actually happened. If your runway is shrinking faster than expected, you need to act immediately — not at the end of the quarter.