Runway & Burn Rate Calculator
How long the money lasts. Net burn, months of runway, and the date you need to have raised or reached profitability by.
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How it works
Gross burn is everything going out; net burn is what is left after revenue. Runway is cash divided by net burn — but only if revenue stays flat, which for a growing company it does not.
Modelling revenue growth changes the answer substantially. A company burning heavily today but growing 10% a month may reach break-even well before the cash runs out, while a flat-revenue company with the same burn simply hits zero on schedule.
Net burn = costs − revenue · Runway = cash ÷ net burn, with revenue compounding monthly
- Gross burn — total monthly operating costs
- Net burn — gross burn less monthly revenue
- Runway — months until cash reaches zero
Worked example
24,000,000 in the bank, 4,200,000 monthly costs, 1,800,000 revenue growing 4% a month against costs growing 2%
Inputs
Results
Revenue is growing twice as fast as costs and it still is not enough — the gap starts too wide. Raising revenue growth to 8% closes it before the money runs out, which is the entire fundraising conversation.
Frequently asked questions
When should I start raising?
Conventional advice is to begin with nine to twelve months of runway left, because a raise routinely takes three to six months and negotiating from a position of scarcity costs you terms. Below six months, your leverage is largely gone.
Should I use gross or net burn for runway?
Net, since revenue genuinely offsets costs. Watch gross burn too, though — it shows what happens if revenue stalls, which is exactly when runway matters most.
Why does the growth rate change the answer so much?
Because it compounds. At 8% a month revenue nearly doubles in nine months, which shrinks net burn every single month. Flat revenue produces a straight-line drawdown; growing revenue produces a curve that may never reach zero.
Is my data sent anywhere?
No. The calculation runs entirely in your browser. Nothing you type is transmitted to us or stored.
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