Burn rate and runway calculator
Free · Runs in your browser · Updated 26 September 2026
Burn rate and runway calculator
- Gross burn
- $70,000 / moWhat you spend, before revenue.
- Net burn
- $50,000 / moSpending minus revenue.
- Runway
- 10 months
- Cash reaches zero
- —Counting from today.
Cash runs out after about 10 months.
| Month | Revenue | Expenses | Burn | Cash left |
|---|---|---|---|---|
| 1 | $20,000 | $70,000 | $50,000 | $450,000 |
| 2 | $20,000 | $70,000 | $50,000 | $400,000 |
| 3 | $20,000 | $70,000 | $50,000 | $350,000 |
| 4 | $20,000 | $70,000 | $50,000 | $300,000 |
| 5 | $20,000 | $70,000 | $50,000 | $250,000 |
| 6 | $20,000 | $70,000 | $50,000 | $200,000 |
| 7 | $20,000 | $70,000 | $50,000 | $150,000 |
| 8 | $20,000 | $70,000 | $50,000 | $100,000 |
| 9 | $20,000 | $70,000 | $50,000 | $50,000 |
| 10 | $20,000 | $70,000 | $50,000 | $0 |
| 11 | $20,000 | $70,000 | $50,000 | −$50,000 (short) |
Cash runs out after about 10 months.
The definitions
Two burn rates and one runway.
Burn and runway
net burn = monthly expenses − monthly revenue
runway (months) = cash ÷ net burn
Example: 500,000 in the bank, 70,000 of monthly expenses and 20,000 of monthly revenue. Gross burn is 70,000, net burn is 50,000, and runway is 500,000 ÷ 50,000 = 10 months.
With growth entered, month 1 uses your figures as they are and each later month multiplies the previous one by 1 plus the rate. The calculator then subtracts each month’s burn from the cash in turn. The runway is the number of whole months the cash covers, plus the fraction of the next month it covers before it runs out.
Reading the result
The zero date is a deadline, not a plan.
- Runway is when the cash is gone, not when you must act. Raising money, cutting costs or reaching profit all take time, so treat the zero date as something to stay well clear of.
- Net burn falls when revenue rises and rises when you hire. If you plan to hire, put that growth in expenses and see how much it shortens the runway.
- Cash is not profit. Customers who pay late, annual plans paid up front and taxes all move cash around; use real monthly cash figures if you have them.
- Everything here is in one currency. Change the symbol to match; the calculator does not convert.
FAQ
Questions people ask first.
- What is the difference between gross burn and net burn?
- Gross burn is everything you spend in a month. Net burn is what you spend minus what you earn, so it is the amount your cash balance actually falls. A business with high spending and high revenue can have a small net burn.
- How do I calculate runway?
- Divide the cash you have by your net burn. With 500,000 in the bank and a net burn of 50,000 a month, you have 10 months. If burn changes month to month, add up each month’s burn until the cash is gone, which is what the table does.
- What if I make a profit?
- Then net burn is negative: your cash grows each month and runway is not a limit. The calculator says so and shows the balance rising.
- Should I include one-off costs?
- Put regular monthly costs in the expenses figure. For a large one-off cost such as equipment or a legal bill, subtract it from your cash first, or the runway will look better than it is.
- How accurate is the growth setting?
- It is a simple compounding rate, applied the same way every month, so it is a way to test a scenario rather than a forecast. Try a fast case and a slow case, and plan around the slow one.
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