Calculate your startup’s monthly burn rate, net burn, and runway. Know exactly how many months of cash you have before you need to raise or reach profitability.
Cash in the bank, and what leaves it each month
What you hold today
$
Total cash and cash equivalents in bank accounts.
Monthly outflow and inflow
$
Total cash spent per month (payroll, rent, software, marketing, etc.).
$
Monthly cash revenue. Leave at 0 for pre-revenue startups.
Cash Runway
8.3
Months of cash left at current net burn rate.
Formula verified 12 September 2026
Net Burn Rate
$60,000
Monthly cash decrease: Expenses − Revenue. The true monthly "bleed."
Approximate cash remaining at the end of each month if net burn stays constant, using the cash balance, expenses, and revenue you entered. Same net-burn logic as the calculator. If revenue covers expenses, the balance holds steady.
Month
Net burn
Cash drawn down
Cash remaining
1
$60,000
$60,000
$440,000
3
$60,000
$180,000
$320,000
6
$60,000
$360,000
$140,000
9
$60,000
$500,000
$0
12
$60,000
$500,000
$0
18
$60,000
$500,000
$0
24
$60,000
$500,000
$0
Estimates only — not financial, tax, or professional advice.
100% private — every number you enter is calculated in your browser and never sent to our servers.
What it calculates: Cash Runway, Net Burn Rate, Gross Burn Rate, Monthly Deficit.
Updated 5 June 2026 · Transparent assumptions
$80,000 goes out; $60,000 is what the bank balance actually loses
Gross burn is total operating spend — $80,000 a month here, regardless of revenue. Net burn subtracts what comes in: $80,000 less $20,000 of revenue is $60,000, and that is the figure the bank balance falls by. Runway divides cash by net burn, so $500,000 lasts 8.3 months.
Both matter, for different reasons. Net burn tells you how long you have. Gross burn tells you how large the cost base is that would have to be cut in a crisis, and it is the number that does not improve just because one large customer paid early. Investors usually ask for net burn and then check gross, because a business with $80,000 of gross burn and $79,000 of lumpy revenue is not as safe as its net figure suggests.
A fundraise takes three to six months, so this company is already in the window
Eight months of runway is not eight months of freedom. Raising a round typically takes three to six months from first conversation to money in the bank, and the process consumes founder time that would otherwise go into the business. Standard practice is to start raising with at least six months left and to treat twelve to eighteen months of runway as the target a round should buy.
The figure also assumes today\u2019s burn holds. Hiring a single additional person at $8,000 a month fully loaded takes runway from 8.3 months to 7.4 — and hiring decisions are usually made months before their cost appears. Running this calculation against planned headcount rather than current headcount is the version that prevents surprises.
Adding $10,000 of monthly revenue buys 1.7 months; cutting $10,000 of cost buys the same
Arithmetically the two are identical: net burn falls by $10,000 either way, and runway rises from 8.3 to 10 months. The difference is what happens next. A cost cut is a one-off improvement that stays flat, while revenue growth compounds — next month\u2019s $10,000 is followed by more.
The practical order is usually to do both, and to be honest about which lever is available on the timescale that matters. Revenue takes months to move; costs can move in weeks. A company with under six months of runway is generally too late to solve it through growth alone, which is the real argument for watching this number well before it becomes urgent.
The same $60,000 means different things depending on what it buys
Burn itself is not a failure — spending ahead of revenue is the entire premise of a venture-funded business. What matters is whether the spending buys something that compounds. Money spent on sales capacity that reliably returns more than it costs is investment; money spent on fixed overhead that does not scale with revenue is drag.
The useful diagnostic is burn multiple: net burn divided by net new recurring revenue added in the same period. A company burning $60,000 to add $60,000 of new annual recurring revenue has a burn multiple of 1, which is strong. Burning $60,000 to add $15,000 is a multiple of 4, which is not, and no amount of runway arithmetic fixes it.
Constant costs, constant revenue, and no lumpy payments
The calculation projects today\u2019s numbers forward unchanged. Real burn is lumpy: annual insurance, tax payments, equipment purchases and hiring all land unevenly, and a month with two of them can consume far more than the average. Runway computed from an average month will be optimistic in exactly the months it matters.
Revenue lumpiness cuts the same way. Annual contracts paid up front make a month look excellent and the following eleven look worse; a single large customer paying late can turn a comfortable position into a scramble. For anything beyond a rough check, model cash month by month against known commitments rather than dividing one balance by one rate.
Sources & References
Figures on this page are checked against primary, authoritative sources. Links open in a new tab.
Results are estimates for planning and analysis based on the figures you enter. They are not accounting, tax, or financial advice — verify with your own records and a qualified professional before making decisions.
Published the calculator with its formula, worked example, assumptions, limitations and a bespoke guide, and added an automated formula test suite covering it.
Separated gross burn from net burn and verified that runway follows net burn, so revenue is not double-counted against the cash balance.
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