SaaS metrics

Startup Runway Calculator

Work out how many months of cash you have left, what your net monthly burn actually is, and the month your balance hits zero. If you are already profitable the calculator says so instead of inventing a deadline.

Runway

Healthy

15.5 months

The standard target after a round. Start the next raise 6 months before the money runs out.

At a net burn of $29,000.00 per month, $450,000 of cash lasts 15.5 months.

Net monthly burn: $29,000
Cash on hand: $450,000
Monthly revenue: $32,000
Monthly expenses: $61,000
Runway in years: 1y 4m
Cash runs out: 2028-01

Cash balance declining toward zero at the current net burn.

View chart data as a table

Month	Cash balance
Month 0	$450,000
Month 1	$421,000
Month 2	$392,000
Month 3	$363,000
Month 4	$334,000
Month 5	$305,000
Month 6	$276,000
Month 7	$247,000
Month 8	$218,000
Month 9	$189,000
Month 10	$160,000
Month 11	$131,000
Month 12	$102,000
Month 13	$73,000
Month 14	$44,000
Month 15	$15,000
Month 16	$0

Runway benchmarks

Runway is months of cash left at the current net burn. The danger is not running out — it is discovering you are short three months before you would close a round, at which point you have no leverage on price or terms.

Stage	Typical runway	Healthy target
Pre-seed / bootstrapped Default-alive beats a rushed raise. Cut scope before you cut the team.	6 - 12 months	18+ months
Seed Enough time to find repeatable acquisition and still raise on milestones.	18 - 24 months	24+ months
Series A Start the next raise with 9 months of cash in the bank.	18 - 24 months	24 - 30 months
Series B+ Longer cycles, larger teams, slower course corrections.	24 - 36 months	30+ months
Profitable / cash-flow positive With net burn at or below zero there is no runway limit — the constraint becomes growth, not survival.	Unlimited	Unlimited

Runway targets reflect standard fundraising advice: hold 12+ months after a round and begin the next raise with at least 6-9 months remaining.

Frequently asked questions

How much runway should a startup have?

Twelve months is the practical minimum and eighteen is the common target after a round. The reason is that fundraising takes three to six months to close, so starting a raise with six months of cash leaves no fallback if the process slips — and it will slip. Twenty-four months gives you room to hit a milestone and raise from a position of strength rather than desperation.

How is runway calculated?

Cash on hand divided by net monthly burn, where net burn is monthly expenses minus monthly revenue. If you have $450,000 in the bank, spend $61,000 a month and collect $32,000, your net burn is $29,000 and your runway is 15.5 months. Every input is in the same period — mixing monthly costs with annual cash produces a number that is wrong by an order of magnitude.

What if my net burn is zero or negative?

Then you are default-alive and the runway is unbounded — you will not run out of cash on the current plan. This calculator returns infinity and says "already profitable" rather than showing a large finite number, because a fabricated deadline gets plotted on charts and drives hiring decisions. When profitable, the real constraint is how fast you choose to grow, not how long you can survive.

Should I use gross or net burn?

Net burn (expenses minus revenue) for runway, because it is what actually moves the bank balance. Gross burn — total expenses with no offset — is useful for a different question: how much you would burn if revenue dropped to zero overnight. Cash divided by gross burn is the conservative "worst case" runway, and it is worth knowing both.

Does runway include committed but unpaid revenue?

No. Signed contracts, unpaid invoices and promised funding are not cash and cannot be spent. Receivables count only when they clear, and a round counts only when the money is in the bank. Counting expected inflows is how companies discover they have three months of runway, not nine.

When should I start raising the next round?

With nine months of runway, and no later than six. A round takes three to six months from first meeting to wire, and the negotiating leverage you have is directly proportional to how much cash you have. At three months of runway you are negotiating from a position where you must accept terms, and investors can price that in.

How to calculate startup runway

The formula

net burn     = monthly expenses - monthly revenue
runway       = cash on hand / net burn     (only when net burn > 0)
zero date    = today + runway months

A worked example. Cash of $450,000, monthly expenses of $61,000 and monthly revenue of $32,000:

Net burn = 61,000 − 32,000 = $29,000 per month
Runway = 450,000 / 29,000 = 15.5 months
Cash reaches zero around 15 months from today

That is a comfortable position but not a safe one. Fundraising takes three to six months, so the raise should begin with nine months of cash remaining — roughly six months from now, which is sooner than it feels.

The profitable case: no runway limit

When revenue covers expenses, net burn is zero or negative and the runway calculation divides by zero or by a negative number. Both are meaningless. Returning a large finite figure such as 120 months is worse than returning nothing, because it looks like a real deadline: it gets plotted, it gets quoted in board decks, and it eventually drives hiring decisions off a number that was never true. This calculator returns infinity and labels it already profitable — no runway limit.

Profitable is not the same as unconstrained, though. It assumes revenue and costs hold at today’s levels. Hiring four people immediately changes the answer, and the change is worth modelling before you sign the offers — which is exactly what the cash curve above shows.

Common mistakes

Counting cash you cannot spend. Receivables, signed-but-unpaid contracts and verbally committed rounds are not runway. Only cleared cash in the bank is.
Forgetting non-payroll costs. Annual software renewals, insurance, accounting and tax payments hit in lumpy months. A burn figure built from payroll alone will understate the true average.
Using gross revenue instead of collected revenue. If you invoice annually and collect up front, your monthly recognised revenue and your monthly cash inflow are different numbers. Runway is about cash.
Assuming the current burn is fixed. It rarely is. Runway is a snapshot; re-run it after any hiring, pricing or significant cost change.
Treating the number as the plan. Twelve months of runway is not a plan, it is a constraint. The plan is what milestone you hit before it expires.

What to do with the result

Under 6 months: cut costs now and open bridge conversations in parallel. At this runway you have no leverage, and delay makes it worse.
6 to 12 months: fundraising should already be your primary job. If the market is cold, prepare a bridge or a revenue-led alternative.
12 to 18 months: healthy. Aim to reach a milestone that changes the valuation narrative before you start the next raise.
Over 18 months: you have room. The question shifts from survival to how aggressively to invest the cash in growth.

Related calculators

Runway and MRR are two ends of the same question, so the MRR calculator is the natural companion — improving monthly revenue extends runway one month at a time. If you are burning cash to acquire customers, check the CAC payback period: a long payback is often the real reason runway is short.

How the runway formula is derived

Step 1 — net burn is the rate the bank balance moves

Runway is a question about cash, so the burn figure has to be a cash figure. What matters is the net movement of the balance, which is what the business spends less what it collects:

net burn = monthly cash expenses - monthly cash collected

With $61,000 of monthly costs and $32,000 collected, net burn is $29,000. Gross burn — the $61,000 with no offset — answers a different and also useful question: how long the company lasts if revenue stopped tomorrow.

Step 2 — divide, but only when the balance is falling

If the balance falls at a constant rate, the number of months until it reaches zero is the balance divided by the rate:

runway (months) = cash on hand / net burn    (valid only while net burn > 0)

The parenthetical is not a footnote. When net burn is zero the balance does not fall and the runway is unbounded; when it is negative the balance rises. The same equation would divide by zero or by a negative number, and reporting the result of that division is how companies end up quoting a runway figure that is arithmetically meaningless. This calculator returns infinity and labels it instead.

Step 3 — the straight line is an approximation

Dividing once assumes both cash and the burn rate stay put. In a growing business the burn shrinks as revenue rises, so the balance does not follow a straight line — it curves, and it reaches zero later than the division suggests:

balance(m) ≈ previous month end revenues - expenses, compounded month by month

That is why this page also plots the balance month by month rather than printing a single number and stopping. The single figure is the convention and is the right thing to compare against the benchmark bands; the curve is the thing to look at before making a hiring decision.

Assumptions and where this breaks

Every model is wrong somewhere. These are the assumptions baked in here, and the situations in which you should not trust the number that comes out.

Assumes

The headline runway holds both revenue and costs flat at today’s levels, which is the standard convention and the only assumption under which a single division is defensible.
Expenses are genuine cash outflows for the period. Non-cash items such as depreciation or accrued but unpaid invoices are not burn.
Revenue counted is cash collected, not revenue recognised. For an annual-plan business these differ sharply in the month a contract is paid.
Cash on hand is money the company can actually spend — cleared, unencumbered, and not reserved for a committed liability.
No further funding is assumed. A signed term sheet is not runway until the wire clears.

Does not apply when

Revenue is growing fast enough that burn falls materially month to month. The flat-burn division then understates runway, and the cash curve shown above is the more honest picture — it plots the balance month by month rather than assuming a straight line.
You are already profitable. Net burn is zero or negative and cash on hand over burn is undefined; the calculator returns infinity and says so rather than inventing a deadline.
You are about to change the cost base. A planned hire, an office lease or a pricing change invalidates the number the moment it takes effect. Re-run it after the decision, not before.
There is committed but uncollected revenue in the pipeline. Receivables and verbally committed rounds are not cash and cannot be spent; counting them is the most common way a nine-month runway turns out to be three.
You need a tax or working-capital-aware number. Estimated tax payments, VAT and payroll cycles make real cash flow lumpy in ways a single monthly net-burn figure cannot capture.

Edge cases handled explicitly

Net burn of zero or below returns Infinity with the label “Already profitable — no runway limit”, rather than a fabricated 120-month figure.
Infinity is never plotted as a data point on the cash curve or rendered as “∞” in the result card.
A zero-revenue company still gets a finite runway, because gross burn is well defined even when net burn equals it.

Where the benchmark numbers come from

The bands in the table above are drawn from the following published sources. They are orientation figures published for the whole industry, not a proprietary dataset and not a target — your own segment, stage and three-month trend matter more than any published band.

Commonly cited fundraising guidance: The “hold 12+ months after a round, start raising with 9 months left” norms come from venture and accelerator advice rather than a single dataset; the benchmark table labels them as guidance.
Y Combinator: Their startup-school material and public writing are a common source for the default-alive / unconstrained-runway framing used for the profitable case.
SaaStr: Operator writing on burn multiple and on the difference between gross and net burn, which the assumptions section calls out.

Where no single institution publishes a figure, this page says so and labels it commonly cited rather than attributing it to a named firm. Nothing on this site is presented as proprietary data we collected.

These six tools are designed to be read as one chain, not six separate numbers:

LTV:CAC → CAC Payback → Quick Ratio → MRR → Churn → Runway

Each tool in the chain is a pure function of the ones before it, which is why the six share one formula module and one set of benchmark bands — the same inputs on different pages cannot disagree here.

Maintained by The SaaS Metrics Calculators Editorial Team

Maintained by the site’s editors, with every formula unit-tested and every benchmark traced to a published source

Formulas and benchmarks last reviewed October 2026.

This page is educational. Every figure is computed in your browser from the inputs you supply, and nothing is checked against your own accounts — treat results as a planning aid, not as financial advice.