Calculate your monthly burn rate and how many months of runway you have.
Calculated instantly in your browser.
How do you calculate burn rate and runway?
Net burn = monthly expenses − monthly revenue, and runway (months) = cash on hand ÷ net burn; if revenue meets or exceeds expenses, runway is effectively unlimited. For example, with $100,000 cash, $10,000 revenue and $30,000 expenses, net burn is $20,000 a month and the runway is 5 months. It shows how long your cash will last.
Understanding your result
Gross burn is total monthly spend; net burn subtracts revenue. Runway is how long your cash covers the net burn at the current rate. Founders usually aim to raise or reach profitability well before runway runs out.
Formula and method
Net burn = monthly expenses − monthly revenue. Runway (months) = cash on hand ÷ net burn. If revenue meets or exceeds expenses, the runway is effectively unlimited.
Assumptions and limitations
Runway here assumes your current cash, revenue and expenses stay flat, which rarely holds. It ignores seasonality, one-off costs, funding rounds, receivable timing and revenue growth or decline. Treat the months shown as a snapshot for planning, not a promise, and rerun it whenever your revenue or spending changes materially.
Worked example
With $100,000 cash, $10,000 revenue and $30,000 expenses, net burn is $20,000 a month and the runway is 5 months.
How to use this tool
- Enter your current cash on hand.
- Enter monthly revenue and expenses.
- Read your net burn and runway.
Common mistakes to avoid
- Using gross burn instead of net burn for runway.
- Ignoring one-off or seasonal costs that change the burn.
About the Burn Rate & Runway Calculator
The Burn Rate & Runway Calculator shows how fast a business is spending its cash and how long that cash will last. Enter your cash on hand, monthly revenue and monthly expenses to get the net burn rate and runway in months.
Who should use this tool
Founders, startup operators and finance teams tracking cash.
Benefits
- Net and gross burn rate.
- Runway in months and years.
- Flags when you are cash-flow positive.
- Simple inputs, instant answer.
Practical use cases
- Knowing how long until you must raise.
- Seeing the runway impact of cutting costs.
- Reporting burn to investors.
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Frequently asked questions
What is the difference between gross and net burn?
Gross burn is your total monthly spend; net burn is spend minus revenue — the cash you actually lose each month.
How much runway should a startup keep?
Many aim for 12–18 months of runway after a raise, leaving time to hit milestones before needing more capital.
Why might my real runway differ from this estimate?
The calculation holds revenue and expenses constant, but real businesses face changing costs, seasonal swings, delayed payments and one-off outlays. Growing revenue extends runway while unexpected spend shortens it. Use the figure as a baseline and update it regularly as your actual cash position and burn rate move.