SaaS Burn Rate & Runway Forecaster

Enter your cash reserves, MRR, monthly expenses, and hiring plans to calculate exact runway, break-even MRR, and whether your startup is default alive or default dead.

Currency

Financial Inputs

Cash on hand

$0 $3M

Please enter a valid value

Monthly revenue (MRR)

$0 $500k

Please enter a valid value

Monthly expenses

$0 $500k

Please enter a valid value

MRR monthly growth

-20% 40%

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Growth scenario

Projected Hiring

Each hire is modeled as its own step-increase in expenses, simulated completely separately from your organic growth runway.

One-time expenses

$0 $100k

Please enter a valid value

Runway Analysis

Company Status Default Alive

Gross Burn Rate $45,000/mo

Net Burn Rate $27,000/mo

Flat Runway 1 year 6.5 mo

Growth-Adjusted Runway 10 years

Hiring-Adjusted Runway 10 years

Break-Even MRR $45,000

Months to Break-Even 1 year 1 mo

Cash Trajectory

Two independent simulations: organic growth alone, and growth plus your hiring plan.

Growth only Growth + hiring plan Cash-out month

Runway Comparison

Flat, growth-adjusted, and hiring-adjusted runway side by side, in months.

Critical (<6mo) Caution (6–12mo) Safe (>12mo)

MRR vs. Expenses — Race to Break-Even

Where the revenue line crosses the expense line, net burn hits zero.

MRR Expenses (incl. hiring) Break-even month

Scenario Comparison

See how conservative, base, and optimistic growth assumptions change your survival timeline, using your cash/MRR/expenses above.

Scenario	Growth	Flat Runway	Adj. Runway	Break-Even	Status
Conservative	3%	18.5	120	32 mo	Default Dead (Flat)
Base Case	8%	18.5	120	13 mo	Default Alive
Optimistic	15%	18.5	120	8 mo	Default Alive

What Is SaaS Burn Rate & Runway?

Burn rate measures how fast your startup consumes cash. Gross burn is total monthly expenses (salaries, hosting, marketing, rent). Net burn subtracts your monthly recurring revenue (MRR) from gross burn — this is the true speed at which your bank balance shrinks.

Runway is the time remaining before cash hits zero. A flat runway assumes MRR and expenses stay constant. A growth-adjusted runway models MRR compounding month over month, which reduces net burn over time and often extends survival by months or years.

In 2026, AI-native SaaS startups face additional variable costs from LLM APIs (OpenAI, Anthropic, DeepSeek). These scale with usage, making burn rate monitoring even more critical than traditional infrastructure costs.

Default Alive vs Default Dead

Coined by Paul Graham, these terms describe your startup's trajectory without external intervention:

Default Alive — Your current revenue growth and expense trajectory will lead to profitability before you run out of cash. No fundraising required.
Default Dead — You will run out of money before reaching profitability unless you raise funding, cut costs, or accelerate revenue dramatically.

The crossover point is your break-even MRR. When monthly revenue equals monthly expenses, net burn becomes zero and runway becomes infinite. Use the hiring model above to see how new headcount pushes that break-even point further into the future — the "Race to Break-Even" chart shows exactly where the two lines cross.

Worked Example: $500K Cash, $18K MRR

An early-stage SaaS company has $500,000 in cash, $45,000 in monthly expenses, $18,000 in MRR, and expects 8% monthly MRR growth.

Net burn: $45,000 − $18,000 = $27,000/month.
Flat runway: $500,000 ÷ $27,000 ≈ 1 year 6.5 mo.

With 8% monthly compounding, MRR crosses $45,000 around month 13. Because break-even arrives before the flat-runway cash-out date, the growth-adjusted runway extends to 10 years — the company is default alive.

Now add two hires in month 4 at $10,000/month fully-loaded cost each. Because hiring is simulated as its own separate scenario — not folded silently into the growth number — you can see exactly how much runway that headcount decision costs versus staying lean.

Frequently Asked Questions

Q: What is startup burn rate?

Burn rate is the speed at which a startup spends its cash reserves before generating positive cash flow. Gross burn is total monthly expenses; net burn is expenses minus monthly recurring revenue (MRR).

Q: How do you calculate cash runway?

Divide your current cash balance by your monthly net burn rate (expenses minus revenue). The result is the number of months you can operate before running out of capital, assuming flat revenue and expenses.

Q: What does "default alive" mean?

"Default alive" means your startup will reach profitability on its current trajectory before cash runs out, without requiring additional funding. "Default dead" means you will run out of money first unless something changes.

Q: What is growth-adjusted runway?

Growth-adjusted runway accounts for MRR increasing month over month. As revenue compounds, net burn shrinks each month, often extending runway significantly beyond the flat calculation.

Q: How does hiring affect runway?

Each new hire increases gross burn by their fully-loaded cost (salary + benefits + taxes). If hiring outpaces revenue growth, runway shortens. This calculator models hiring as step increases in monthly expenses starting in a specified month, and simulates it completely separately from your organic growth runway.

Q: What is a safe cash runway length?

Most investors and advisors recommend at least 12–18 months of runway. Below 6 months is considered critical and should trigger immediate cost reduction or fundraising efforts.

Q: Can a startup have a negative burn rate?

Yes. When MRR exceeds monthly expenses, net burn becomes negative — meaning the company is cash-flow positive and its cash balance grows each month rather than shrinking.

Q: What is break-even MRR?

Break-even MRR is the monthly recurring revenue required to cover all operating expenses, resulting in a net burn of zero. Above this threshold, the company is default alive.