Burn Rate Calculator
Burn rate is how much cash a company spends each month. Gross burn is total monthly cash outflow; net burn is outflow minus cash coming in. This burn rate calculator works out both, then divides your cash balance by net burn to show your runway – how many months the money lasts if nothing changes.
Use the calculator above for your own numbers. Below, we explain how the Burn Rate calculator works, with worked examples and sources.
Gross burn vs net burn
Gross burn is everything you pay out in a month – salaries, rent, software, contractors, marketing. Net burn subtracts cash coming in from customers. A company spending $80,000 a month with $30,000 of revenue has a gross burn of $80,000 and a net burn of $50,000. Investors focus on net burn for runway, but gross burn shows how much of the cost base you would need to cut if revenue fell.
How to calculate burn rate and runway
- Use cash, not accounting profit: include payments for equipment and loan repayments, and exclude non-cash items such as depreciation and stock-based compensation.
- Average over three months to smooth one-off payments such as annual software bills or tax.
- Net burn = cash out − cash in. Or: (balance three months ago − balance today) ÷ 3.
- Runway = cash today ÷ net burn.
Example: cash fell from $600,000 to $450,000 over three months. Net burn = $150,000 ÷ 3 = $50,000 a month, so $450,000 lasts nine months at that pace.
Runway when revenue is growing
Simple runway assumes nothing changes. If revenue grows, net burn shrinks each month and runway is longer. The scenario mode projects month by month: costs plus planned hires, minus revenue growing at your chosen rate, until cash runs out or the company reaches break-even. If break-even arrives before the cash runs out, the business is sometimes described as 'default alive'; if not, it needs new funding or cuts – 'default dead'.
Burn multiple
Burn multiple compares how much you burn with how much new annual recurring revenue (ARR) you add: net burn ÷ net new ARR over the same period. Burning $150,000 in a quarter to add $100,000 of ARR gives a burn multiple of 1.5. Lower means more efficient growth; it is most meaningful for subscription businesses.
How to extend your runway
- Cut or pause the costs that do not drive revenue or product progress – often software subscriptions, agencies and travel first.
- Delay hires and model each one in the scenario tool before committing.
- Collect cash faster: annual upfront billing, shorter payment terms, chasing overdue invoices.
- Negotiate payment terms with suppliers and landlords.
- Start fundraising well before you need it – raises commonly take several months – so plan to begin with plenty of runway left.
Runway projection example
A start-up has $450,000 in the bank, costs of $80,000 a month and $30,000 of monthly revenue growing 10% a month. Simple runway says 9 months ($450,000 ÷ $50,000). But because revenue grows, net burn falls each month: about $47,000 in month 2, $40,000 in month 4, $27,000 in month 7 and just over $2,000 in month 11. In month 12 revenue (about $85,600) exceeds costs, and the company becomes cash-flow positive with roughly $126,000 still in the bank. On these assumptions it is 'default alive' – but if growth were 5% a month instead, the cash would run out first. The scenario mode lets you test both.
What to include – and leave out – of burn
| Include | Exclude |
|---|---|
| Salaries, payroll taxes and benefits | Depreciation and amortisation |
| Rent, utilities and software | Stock-based compensation (no cash leaves) |
| Contractors, agencies and marketing | New equity raised (it adds to cash, it is not revenue) |
| Equipment purchases and loan repayments | One-off grants – track separately |
| Taxes and interest actually paid | Accounts payable not yet paid (until it is paid) |
If you take on debt or raise a round, add the new cash to your balance rather than to revenue, so that burn still reflects the underlying business. Track gross burn, net burn and runway each month on the same basis so trends are meaningful.
Personal burn rate
The same idea works for individuals: your personal burn rate is your monthly spending, and your runway is savings ÷ (spending − income). Someone with $18,000 of savings, $3,000 of monthly expenses and $1,500 of part-time income has a net burn of $1,500 and about 12 months of runway – useful for planning a career break or a freelance start.
A planning tool, not financial advice. Last reviewed: .

Written & built by
Zeeshan Nawaz
Calculator Developer · Tuff Search
Builds and tests Tuff Search calculators, turning official tax tables and published formulas into tools anyone can check.
FAQ
Frequently asked questions
Quick answers about the Burn Rate calculator.
The amount of cash a business spends per month. Net burn subtracts incoming cash; gross burn does not.
Net burn = monthly cash spent − monthly cash received, or the fall in your cash balance over a period divided by the number of months.
How many months your cash will last at the current net burn: cash balance ÷ net burn.
There is no universal number. What matters is runway relative to your next milestone and how efficiently the spending creates growth – for example, a low burn multiple.
If cash coming in exceeds cash going out, net burn is negative – the business is cash-flow positive and runway is not limited by burn.
Monthly, after closing the books, and whenever you plan a big hire or contract.
Many founders and investors aim for 18–24 months after a fundraise, so there is time to hit milestones and raise again; the right figure depends on the business.
Still have a question? Email support@tuffsearch.com
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