Calculate your startup's runway with scenario modeling, revenue growth projections, and fundraising requirements. Plan your path to profitability or your next fundraise.
REVENUE MODELING
Formula:
Runway = Cash / (Burn - Revenue)
Enter your cash balance and burn rate
Add revenue for growth projections
Startup runway is the single most critical metric for any venture-backed company. It represents the number of months your startup can continue operating before exhausting its cash reserves. Per Y Combinator, runway is the primary determinant of whether a startup survives long enough to achieve product-market fit or raise its next round of funding.
The concept of runway directly ties to burn rate, which measures how quickly a company consumes its cash reserves. Understanding the relationship between runway and burn rate is essential for founders making strategic decisions about hiring, marketing spend, and product development velocity. A startup with $2 million in the bank and a $200,000 monthly burn rate has exactly 10 months of runway, assuming no changes in revenue or expenses.
According to Sequoia Capital, the ideal runway varies by stage and market conditions. In favorable funding environments, 18 months may suffice, but during downturns, 24-30 months provides necessary safety margin. The key insight is that runway is not just about survival, it is about having enough time to achieve meaningful milestones that justify your next fundraise at a higher valuation.
Revenue growth fundamentally changes runway calculations. A startup generating growing MRR will see its net burn decrease over time, extending runway beyond simple cash-divided-by-burn projections. This is why sophisticated runway calculators model multiple scenarios with different growth assumptions. The path from current state to profitability or next fundraise rarely follows a linear trajectory.
Basic Runway = Current Cash / Net Burn Rate
Where Net Burn Rate equals:
Net Burn = Monthly Expenses - Monthly Revenue
Sum all liquid assets including bank accounts, money market funds, and any short-term investments that can be converted to cash within 30 days. This is your starting runway base.
Add all recurring monthly expenses: salaries, benefits, rent, software subscriptions, marketing spend, hosting costs, legal and accounting fees. Be comprehensive and include quarterly or annual expenses divided into monthly equivalents.
Calculate your actual monthly revenue using your MRR calculator. Subtract this from gross burn to get net burn. If net burn is negative, you are cash flow positive and technically have infinite runway.
Project how revenue will change over time. Conservative scenarios assume current growth rates decline, moderate scenarios maintain current trajectories, and aggressive scenarios project acceleration. Each scenario produces different runway projections.
Based on your chosen scenario, calculate the specific month when cash reserves will be exhausted. This date is critical for planning fundraising timelines, as you should begin raising 6-9 months before this point.
While runway and burn rate are closely related, they measure fundamentally different aspects of startup financial health. Understanding this distinction is crucial for making informed decisions about growth strategy and fundraising timing.
A startup can have high burn rate but long runway (well-capitalized), or low burn rate but short runway (underfunded). The optimal combination depends on market opportunity, competitive dynamics, and fundraising environment. Use a burn rate model to analyze your monthly cash consumption in detail.
A B2B SaaS company has raised $1.5M seed funding, has $25K MRR growing 15% monthly, and burns $120K per month.
With 15% monthly revenue growth, this startup will reach breakeven in approximately 14 months. They should begin Series A fundraising now, targeting close in 4-6 months while revenue metrics are still improving.
A consumer mobile app has raised $8M Series A, generates $150K monthly revenue, and has aggressive growth spending of $500K per month.
This company has strong runway but high burn. If growth targets are not met, they may need to cut burn to extend runway. The key metric to watch is whether CAC payback is improving with scale.
A bootstrapped company has $200K in savings, $80K MRR, and currently spends $70K monthly, making it slightly profitable.
This company has infinite runway and is growing organically. If they raise venture capital to accelerate growth, they should calculate how increased burn affects runway and what milestones justify the dilution. Calculate potential dilution with a simple dilution model.
Industry standards from Y Combinator, Sequoia Capital, and other top venture firms suggest different runway targets based on company stage and market conditions.
Focus on MVP and initial traction
Achieve product-market fit signals
Scale repeatable growth engine
Accelerate market dominance
While runway calculations are essential for financial planning, they have inherent limitations that founders and investors should understand when making strategic decisions.
Basic runway calculations assume constant monthly burn. In reality, expenses fluctuate due to hiring spikes, one-time costs, seasonal marketing spend, and infrastructure investments. Build buffer for unpredictable expenses.
Projecting future revenue growth is inherently uncertain. External factors like economic conditions, competitive dynamics, and market shifts can dramatically impact growth rates. Model multiple scenarios rather than relying on single projections.
Runway calculations do not account for the fact that fundraising becomes harder as runway decreases. Investors prefer companies with 12+ months runway, creating a cliff effect where options narrow rapidly below certain thresholds.
Revenue recognition and cash collection are not the same. Enterprise SaaS companies often have 30-90 day payment terms, meaning booked revenue may not convert to cash for months. Track actual cash collections separately.
Simple runway metrics do not show what costs are variable versus fixed, or how quickly a company could cut burn if needed. Understanding expense flexibility is as important as knowing current runway.
For more guidance, visit the Planning tools hub.
For fundraising benchmarks and runway targets, visit the Startup tools hub .
Pair this tool with the Market Share Calculator and the Revenue Growth Calculator to cross-check inputs. For strategic context, read our founder's LOI negotiation guide and explore the Business Planning tools hub.
Target 18-24 months runway post-funding to give adequate time for hitting milestones and raising your next round. Shorter runway creates fundraising pressure and weakens negotiating position.
Start fundraising with 9-12 months runway remaining. The fundraising process typically takes 4-6 months, and you need buffer for unexpected delays or market shifts.
Model multiple scenarios including conservative, moderate, and aggressive growth assumptions. Runway is not a single number but a range based on execution outcomes.
Revenue growth dramatically extends runway. A startup with 10% monthly growth will have significantly longer runway than one with flat revenue, even with identical starting positions.
Know your levers for extending runway: cost cuts, payment term renegotiation, bridge financing, and revenue acceleration. Have contingency plans before they are needed.
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