OnSumoTools

Burn Rate & Runway Calculator

Walk cash down month by month with optional revenue compounding, gross burn, net burn, runway headline, and a four-row scenario table.

100% client-side. Inputs stay in your browser (ons-burn-rate-inputs).

Model net burn with optional month-over-month revenue growth, then read runway from a month-by-month cash walk, not a single static divisor when growth is on.

Inputs

You have about 17.0 months of runway.

Naive constant-burn runway (month-1 net burn only): 12.5 months, iteration above accounts for revenue growth month by month.

Cash balance

$500,000

Gross burn

$60,000

Net burn (month 1)

$40,000

Break-even month

Month 24

Cash balance over time

Orange line marks the first month where modeled revenue meets or exceeds operating costs.

Scenario comparison

Same growth assumption; costs or starting revenue shift per row.

ScenarioNet burn (month 1)Runway
Current plan$40,00017.0 mo
Operating costs −10%$34,00010+ years
Operating costs −25%$25,00010+ years
Monthly revenue +20%$36,00010+ years

Under about 12 months of simple (constant) net burn is a common healthy SaaS growth benchmark, your iterated runway above is the headline when growth is on.

How does the Burn Rate & Runway Calculator work step by step?

The calculator starts with two numbers: what you spend each month (gross burn) and what you earn (revenue). Net burn = monthly costs minus monthly revenue. A simple runway estimate divides your cash balance by net burn, but simple division ignores revenue growth. The tool handles this by iterating forward month by month: it applies your growth rate to revenue each month, recalculates net burn, and subtracts it from remaining cash until the balance hits zero or 120 months. With revenue growth factored in, runway extends beyond the simple estimate because each month the burn gets smaller. The scenario comparison table runs the same month-by-month projection under four conditions: current burn, costs cut 10%, costs cut 25%, and revenue up 20%. If revenue already exceeds costs, the calculator shows: Break-even. Runway is indefinite.

What does a typical Burn Rate & Runway Calculator result look like?

Cash balance $500,000. Monthly revenue $20,000. Monthly costs $60,000. Revenue growth 5% per month. Simple runway: $500,000 / $40,000 = 12.5 months. With 5% growth applied month by month, cash runs out at approximately month 16 instead of 12.5. Break-even (where revenue reaches $60,000) occurs around month 23, but cash runs out first at month 16. Cutting costs 25% extends runway to approximately 25 months. Revenue up 20% extends to approximately 18 months.

Frequently asked questions

  • What is burn rate?

    Burn rate is how much cash your company spends beyond what it earns each month. Gross burn is your total monthly expenses. Net burn subtracts your revenue from expenses. A startup with $80,000 in costs and $30,000 in revenue has a net burn of $50,000 per month.

  • What is a healthy runway for a startup?

    18 to 24 months is the standard recommendation from most venture investors. This gives you enough time to hit key milestones and start a fundraise 6 to 9 months before you run out. Below 12 months, you should already be fundraising or cutting costs. Use this metric consistently over time to track improvement rather than optimizing for a single period's snapshot.

  • How do I extend my runway?

    Two paths: cut costs (faster effect, immediate runway extension) or grow revenue (slower but compounds over time). Most founders combine both. The scenario table in this calculator shows the impact of each approach so you can prioritize. Run the calculation monthly to track trend direction rather than relying on a single data point.

  • When should I start fundraising?

    When you have 9 to 12 months of runway remaining. Most fundraising rounds take 3 to 6 months from first meeting to wire. Starting at 6 months or less puts you in a weak negotiating position because investors know you are running out of time. Revisit this decision as your situation changes; the right answer today may differ from the right answer in 12 months.

  • What is the difference between gross burn and net burn?

    Gross burn is your total monthly spending regardless of income. Net burn subtracts revenue from that total. Investors care more about net burn because it reflects how fast you are actually consuming cash. A company with $100,000 gross burn and $70,000 revenue has only $30,000 net burn. Use this metric consistently over time to track improvement rather than optimizing for a single period's snapshot.

  • Should I include one-time expenses?

    No. Burn rate measures your recurring monthly run rate. One-time costs like equipment purchases, legal fees, or moving expenses should be handled separately. If you have a large one-time expense coming, subtract it from your cash balance before entering it into the calculator. Test both approaches with real data from your business before committing to a single strategy.

Related tools

How many months of cash are left?

Burn rate is the cash you lose each month. Runway is how long you can keep going before the bank account hits zero. They're the two numbers every founder needs close at hand.

Enter cash in the bank, monthly costs and revenue, plus expected revenue growth. The calculator projects cash month by month and marks the break-even point on a chart. Four scenario rows let you compare plans.

Gross burn versus net burn

Gross burn is everything you spend. Net burn is spending minus revenue. If you spend 80,000 and earn 30,000, net burn is 50,000. With 600,000 in the bank, runway is 12 months. But if revenue grows by 5 percent a month, runway stretches, and the tool shows by how much.

Don't mix the two up when you talk to investors. Runway is almost always based on net burn.

  • Aim for 18 months or more of runway after a raise
  • Start fundraising with at least 9 to 12 months of cash left
  • Strip out one-time costs from regular burn, and plan them separately

Stretching your runway

Cut spending that doesn't drive growth. Raise prices. Push for annual prepayment from customers. Reduce churn, since a saved customer is worth more than a new one. Delay hires until revenue supports them.

Be honest with growth assumptions. A model that assumes 20 percent monthly growth forever will lie to you. Run a flat case and a slow case.

Your numbers stay in your browser.