Summary

This burn rate calculator takes six inputs (cash, monthly revenue, payroll, other costs, revenue growth and a cost scenario) and returns gross burn, net burn, runway in months, burn multiple and a raise-timing signal. Runway is shown at current burn and projected month by month with growth. Everything runs in your browser, nothing is stored.

Free runway tool

Burn Rate Calculator: Net Burn, Runway, Burn Multiple

Enter cash, revenue and costs. Get gross and net burn, runway in months and your burn multiple. No signup, computed in your browser.

Calculate my burn

Calculate your burn rate and runway

Six inputs, live results. The defaults model a seed-stage AI startup with $1.2M in the bank. Replace them with your own numbers.

Gross burnper month
Net burnper month
Runway, current burncash / net burn
Runway, with growthmonth-by-month projection
Burn multiple
Start raising inwhen 9 months of runway remain
Projected cash balance, next 12 months
How it works

What the calculator measures, and how

Gross burn and net burn

Gross burn is payroll plus every other monthly cost. Net burn subtracts monthly revenue. If revenue exceeds costs, net burn turns negative and the tool tells you the business is cash generating.

Two runway figures

Current-burn runway is cash divided by net burn, a single division. Growth-adjusted runway projects each month forward with your revenue growth and the cost scenario you pick, so it reflects where burn is heading, not where it stands.

Burn multiple

Net burn divided by net new ARR, with net new ARR estimated as monthly revenue times your growth rate times twelve. It shows how many dollars you burn for each dollar of annual recurring revenue you add.

Raise-timing signal

The tool flags when 9 months of runway remain. Fundraising commonly takes 3 to 6 months from first meeting to wire, so that date is the latest sensible moment to start, not a comfortable one.

Reading the output

What a number means once you have it

A runway figure on its own tells you little. The delta between current-burn runway and growth-adjusted runway is the useful part. If the growth-adjusted figure is longer, revenue is outpacing cost growth and your burn is shrinking. If it is shorter, costs are compounding faster than revenue and the flat number is flattering you. For AI startups the second case is common, because inference and cloud spend scale with usage while revenue lags a billing cycle behind.

  • Runway under 6 months: extend runway before anything else.
  • 6 to 12 months: you are inside the fundraising window.
  • 12 to 18 months: plan the raise or the cost cut now.
  • 18 to 24 months or more: healthy, negotiate from strength.
Hourglass beside a stack of coins and a calculator representing startup runway
Method

How to get inputs you can defend

  1. 1

    Use cash, not book value

    Take the bank balance from your last statement, net of any amounts owed within 30 days such as payroll taxes or a card balance. Investors will check it against statements.

  2. 2

    Average revenue over three months

    Use recognised MRR, not bookings or pipeline. Averaging three months smooths one-off invoices and gives a number an analyst will accept.

  3. 3

    Split payroll from the rest

    Payroll and contractors usually carry the highest fixed share. Everything else, including cloud, inference, software and rent, goes in the second field. Add recurring debt payments there too.

  4. 4

    Run all three cost scenarios

    Switch between flat, steady hiring and fast hiring. The spread between the three results is your planning range. Present the middle one and know the other two.

Burn rate calculator questions

What is a burn rate calculator?
A burn rate calculator takes the cash you hold, your monthly revenue and your monthly costs, then returns how much cash you lose each month and how many months you can operate before the balance reaches zero. This one also projects the balance month by month with revenue and cost growth, and computes your burn multiple.
What is the difference between gross burn and net burn?
Gross burn is total monthly spending: payroll, contractors, cloud and inference bills, tools, rent. Net burn is gross burn minus monthly revenue. Runway is always computed on net burn, because revenue offsets part of what you spend.
How is runway calculated here?
The current-burn figure divides cash by net burn. The growth-adjusted figure steps forward one month at a time: revenue grows at your chosen rate, costs grow at the scenario rate, and the cash balance is reduced by that month's net burn until it hits zero. If revenue overtakes costs first, the tool reports 60+ months.
What is a good burn multiple?
Burn multiple is net burn divided by net new ARR over the same period. The scale popularised by David Sacks of Craft Ventures reads under 1 as amazing, 1 to 1.5 as great, 1.5 to 2 as good, 2 to 3 as suspect and above 3 as bad. It matters most from the Series A stage onward, when investors price efficiency.
How many months of runway should an AI startup keep?
A commonly cited target is 18 to 24 months right after a raise, and a floor of 6 to 9 months before you must be closing the next round. AI startups should add margin for inference costs, which scale with usage and can move faster than headcount.
Is my data stored or sent anywhere?
No. The calculation runs entirely in your browser. Nothing you type is saved or transmitted, apart from an anonymous counter that records that the tool was used.
Why does the growth scenario change my runway so much?
Compounding. Costs growing 5% per month double in about 14 months, while a flat burn stays flat. Revenue growing faster than costs shrinks net burn each month and can push the zero-cash date out of reach. Test all three cost scenarios before you present a runway number to anyone.
Does this include one-off costs such as taxes, debt service or capex?
Not directly. Add recurring debt payments or annual tax installments, divided by twelve, to the other monthly costs field. One-off purchases are better handled by reducing the cash balance before you calculate.

Runway known. Now model what a raise costs you.

Use the dilution calculator to see how much ownership a round at your target valuation takes from the founders.

Open the dilution calculator
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