Cash Burn & Runway Calculator

Use this cash runway calculator to see how many months of cash your business has left: enter your balance, spending and revenue to plan ahead.

What it does

The Cash Burn & Runway Calculator shows how many months a business can keep operating before it runs out of cash. It compares the money in the bank against net monthly spending after any revenue.

Data sources & parameters

This calculator uses standard financial formulas and runs entirely in your browser. It needs no external rate data — your result is computed only from the values you enter above.

We always strive to use the latest data for every variable so our results and reports are as accurate as possible. Even so, errors are possible — you should not rely on this tool or its report alone, and we accept no liability for any decision made based on it.

The formula

runway_months = cash_balance ÷ (monthly_burn − monthly_revenue)

How it works

It subtracts monthly revenue from monthly spending to find the net burn, then divides the cash balance by that net burn to show how many months, and years, of runway remain.

Where it is used

Knowing how long a startup can operate before needing to raise or break even
Planning a fundraise timeline with a safety margin before cash runs out
Testing how cutting costs or adding revenue extends the runway

Worked example

A startup holds $500,000.00 and spends $50,000.00 a month with no revenue yet. Net burn is …, leaving … months of runway — about … years before the cash is gone.

What the cash burn and runway calculator does

Enter your cash balance (all cash and equivalents you can actually access), your total monthly spending, and your monthly revenue, or zero if you have none yet. The calculator shows your net monthly burn and how many months and years of runway remain. For a startup, runway is the time available to reach the next milestone, close a funding round or become profitable, and it affects decisions on hiring, spending and fundraising.

How runway is calculated

Net burn is the cash that leaves the business each month after revenue. Spend 50,000 a month and bring in 10,000, and net burn is 40,000. Runway is your cash divided by net burn: a balance of 480,000 at 40,000 a month gives twelve months. The calculation is plain arithmetic and works in any currency.

Gross burn versus net burn

Gross burn is total monthly outflow: every salary, subscription and bill. Net burn subtracts revenue, and it is what determines runway. A company that spends heavily but earns almost as much has a long runway, while one with modest spending and no revenue can use up its cash quickly. Gross burn shows how expensive the business is to run; net burn shows how fast the balance is shrinking.

Why runway matters

With eighteen months of runway you can invest in growth, take measured risks and raise money from a position of strength. With three months, every decision becomes urgent and defensive, and investors notice. Running out of cash before the business can prove itself is the most common way otherwise promising companies fail, so watch runway closely and act well before it gets short.

Extending your runway

You can lower net burn or increase cash. Lowering burn is usually faster and within your control: cut non-essential costs, renegotiate contracts, slow hiring, delay large purchases. Growing revenue lowers net burn from the other side, by the full amount of each extra unit of income. Raising capital adds cash but is slower and less certain, so start early; many founders aim to keep twelve to eighteen months of runway so a fundraise or pivot never happens in a panic. Try cutting spending by ten percent, or adding revenue from a new deal, to see how many months it adds.

Reading the result

The figure is a snapshot of today's numbers. Spending rises as you hire, revenue grows as you sell, and one-off costs distort any single month. Model a conservative case, with flat revenue and rising costs, and an optimistic one with growth; reality usually falls between them. Update the calculation each month with actual figures, and treat a steadily shrinking runway as an early warning.

This article is general information only and is not financial or business advice.

About This Cash Runway Calculator

Use this cash runway calculator to get an instant estimate based on the figures you enter. Adjust the inputs above to match your situation, or browse all our calculators to plan your next step.

Frequently asked questions

How does the cash runway calculator work?

It subtracts your monthly revenue from your monthly spending to find your net burn rate, then divides your cash balance by that figure. The result is the number of months your business can keep operating at the current pace before the cash runs out, shown in both months and years.

What is the difference between gross burn and net burn?

Gross burn is the total cash you spend each month regardless of income. Net burn is that spending minus the revenue you bring in. Runway is driven by net burn, because incoming revenue offsets some of the outflow and stretches how long your cash lasts.

What happens if my revenue is higher than my spending?

Then your net burn is zero or negative, which means you are cash-flow positive and no longer burning through your balance. In that case the runway is effectively unlimited, and the calculator reports it as zero months of burn instead of a countdown.

How much runway should a startup keep?

Many investors suggest keeping 12 to 18 months of runway so you have time to hit milestones and raise the next round without operating in crisis mode. The right buffer depends on your fundraising climate, growth stage, and how predictable your spending is.

How can I extend my runway?

You extend runway by lowering net burn or raising your cash balance. That means cutting non-essential costs, growing revenue, delaying large purchases, or raising capital. Even a small reduction in monthly spending can add several months to how long your cash lasts.

Is my data kept private?

Yes. The calculation runs entirely in your browser. Nothing you enter is uploaded, stored, or shared with anyone.

About the author

Written and reviewed by

Taha Kheirandish

Economics student and independent researcher

Taha Kheirandish reads tax codes the way other people read maps — to find out where a system actually leads, not where it claims to go.

He is an economics student, and his work here is comparative by design. A pension deferral bonus in Quebec, a commuting allowance in Germany, a rent-increase ceiling in the Netherlands: each is a decision a government made about how money should move, and each reads differently once you set it beside eight others. He builds and checks these calculators across nine markets from primary sources — the regulation rather than a summary of it, the ministry’s own circular rather than a news item quoting it.

That is the editorial standard of the site as well as his habit. Every rate, threshold and bracket here carries the document it was read from and the date it takes effect, and gets re-checked when the law moves rather than when someone happens to notice.

He is a researcher, not a licensed adviser, and nothing on this site is personal financial advice. It is arithmetic done carefully with its sources shown — so that you can check it, and take it to someone who is.

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