Burn Rate & Runway Calculator
Calculate gross burn, net burn and how many months of runway your cash buys, with optional monthly revenue and expense growth modelled month by month.
At these growth rates the account reaches zero around Jul 2, 2027 — about 0.9 years away. Most investors want a raise closed with at least six months of runway still in hand.
| Month | Revenue | Expenses | Net burn | Ending cash |
|---|---|---|---|---|
| 1 | $40,000 | $120,000 | $80,000 | $670,000 |
| 2 | $43,200 | $122,400 | $79,200 | $590,800 |
| 3 | $46,656 | $124,848 | $78,192 | $512,608 |
| 4 | $50,388 | $127,345 | $76,956 | $435,652 |
| 5 | $54,420 | $129,892 | $75,472 | $360,179 |
| 6 | $58,773 | $132,490 | $73,717 | $286,463 |
| 7 | $63,475 | $135,139 | $71,665 | $214,798 |
| 8 | $68,553 | $137,842 | $69,289 | $145,509 |
| 9 | $74,037 | $140,599 | $66,562 | $78,947 |
| 10 | $79,960 | $143,411 | $63,451 | $15,496 |
| 11 | $86,357 | $146,279 | $59,922 | $-44,426 |
Gross burn is total cash out per month; net burn is cash out minus cash in. Runway is cash divided by net burn, so it only exists while net burn is positive. The projection assumes growth compounds monthly and ignores one-off inflows such as a funding round or a tax refund — add those to your cash figure yourself. Nothing is uploaded; the model runs in your browser.
What is the Burn Rate & Runway Calculator?
The ByteTools Burn Rate Calculator answers the question every founder asks before a board meeting: how long does the money last?
- Gross burn and net burn shown separately
- Flat runway alongside runway with compounding growth
- Projected zero-cash date in plain language
- 36-month projection table with ending cash each month
- Handles the profitable case where there is no net burn
- All figures stay in your browser — nothing is uploaded
How to use the Burn Rate & Runway Calculator
- 1
Enter your current cash balance and pick a currency.
- 2
Enter monthly revenue actually collected and total monthly operating expenses.
- 3
Set the monthly growth rate you expect for revenue and for expenses.
- 4
Read gross burn, net burn, flat runway and runway with growth.
- 5
Scan the month-by-month table to see when the balance turns negative.
About the Burn Rate & Runway Calculator
The ByteTools Burn Rate Calculator answers the question every founder asks before a board meeting: how long does the money last? Enter your cash balance, monthly revenue and monthly operating expenses and it reports gross burn, net burn and your runway in months.
Because a real business is not static, you can also set a monthly revenue growth rate and expense growth rate. The tool then walks the balance forward month by month, compounding both, and shows the month your cash reaches zero along with a full projection table.
It is deliberately conservative about what it knows: growth rates and figures are all typed by you, no funding rounds or one-off inflows are assumed, and no live financial data is fetched. Everything runs in your browser, so your cash position is never uploaded.
Frequently asked questions
What is the difference between gross burn and net burn?
Gross burn is every dollar leaving the business each month — total operating expenses. Net burn subtracts the revenue coming in, so it is expenses minus revenue. Runway is always calculated from net burn, because that is the rate your bank balance actually falls.
How do you calculate runway?
Divide your cash balance by your monthly net burn. $750,000 in the bank against a $80,000 net burn is roughly 9.4 months of runway. Runway only exists while net burn is positive — once revenue covers expenses, there is no burn to divide by.
How much runway should a startup have?
The widely used rule of thumb is to raise before you drop under six months, since a funding round routinely takes three to six months to close. Many investors want to see 18 to 24 months of runway immediately after a round.
Why does the growth projection give a different runway?
The flat figure assumes today's revenue and expenses hold forever. The projection compounds both growth rates each month, so growing revenue extends the runway and growing costs shorten it — often dramatically over a two-year horizon.
Does this account for a funding round or a tax refund?
No. One-off inflows are not modelled, so add them to your cash balance yourself before reading the runway. The tool only compounds the recurring revenue and expense figures you enter.
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