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Burn Rate & Runway Calculator

Work out net burn, how many months of runway you have left, and the date the cash runs out.

Your details

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$
$

Trajectory

%
%

Hiring, infrastructure and everything else creeping upward

This calculator runs entirely on your device. Nothing you enter is uploaded, stored, or sold. How this works

Runway

9 months

Cash reaches zero around May 2027

Save these results

Includes your inputs, the full breakdown, and every row of the table.

Gross burn

$125,000/mo

Net burn

$85,000/mo

Runway at today's burn

8.8 months

Break-even

Not reached

Projected cash balance
$0$188k$375k$563k$750k024689
Cash
Cash
Breakdown
Cash on hand
$750,000
Monthly revenue
$40,000
Monthly expenses
- $125,000
Net burn per month
- $85,000
Month by month
MonthRevenueExpensesNetCash left
Month 1$40,000$125,000- $85,000$665,000
Month 2$42,400$127,500- $85,100$579,900
Month 3$44,944$130,050- $85,106$494,794
Month 4$47,641$132,651- $85,010$409,784
Month 5$50,499$135,304- $84,805$324,979
Month 6$53,529$138,010- $84,481$240,498
Month 7$56,741$140,770- $84,030$156,468
Month 8$60,145$143,586- $83,440$73,028

What this means

  • Raise while you still have nine to twelve months of runway. Negotiating from a position where you can walk away is worth more than any pitch deck.
  • Gross burn is what you spend; net burn is what you spend minus what you earn. Investors usually mean net burn, but gross burn is the number that matters if revenue is volatile.
  • This assumes smooth growth. Real revenue is lumpy, and annual contracts, seasonality and churn all distort the curve.

How the burn rate & runway calculation works

Runway is the single most important number in an early company, because it converts every other decision into a deadline. It is simply the cash you hold divided by the rate you are consuming it, but the naive version of that calculation is optimistic in one direction and pessimistic in the other: expenses tend to grow as you hire, while revenue growth compounds in your favour. Modelling both is the difference between a useful projection and a comforting one.

The distinction between gross and net burn matters more than it first appears. Gross burn is total operating spend, and it is what you actually have to fund if revenue stops. Net burn subtracts revenue and is the figure most people quote. A company with high gross burn largely covered by revenue looks efficient on a net basis but is fragile, because losing a single large customer moves the runway dramatically.

Frequently asked questions

When should I start raising?

When you have around nine to twelve months of runway left. A round routinely takes three to six months from first meeting to funds landing, and the last thing you want is to be negotiating terms while payroll is in question. Investors can sense desperation, and it shows up in the valuation.

Should I look at gross or net burn?

Both, for different reasons. Net burn tells you how long the cash lasts on current performance. Gross burn tells you how exposed you are if revenue drops, which is the scenario that actually kills companies. If a single customer leaving would move you from twenty months of runway to eight, you are running on gross burn whether you say so or not.

Does the growth rate assumption matter much?

Enormously, and that is precisely why you should treat the output as a range rather than a date. Run it once with your plan's growth rate and once with growth at zero. If those two scenarios lead to very different decisions, you are relying on growth you have not yet earned.

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Disclaimer. This calculator is provided for general information and educational purposes only and does not constitute financial, tax, legal, medical, or engineering advice. Results are estimates based on the inputs you provide and the assumptions described above. Confirm any figure with a qualified professional before acting on it.