Cash & runway
Burn Rate Calculator
Separate the cash you spend from the cash you keep after revenue, then optionally attach a cash balance to see months remaining.
Decision: How fast is the business consuming cash?
This tool runs in your browser. FounderMage does not send the numbers you enter to our servers.
Result
Gross burn
Gross burn: $40,000.00
Net burn
Net burn: $25,000.00
Runway at this net burn
Runway at this net burn: 8 months
How to read the result
Net burn is the monthly cash gap from the numbers you typed. It is not a verdict on whether spending is justified.
Calculated facts
Totals and thresholds come only from the values on this page. They describe the math, not what you should do.
Still a judgment call
Risk, timing, customers, and judgment stay outside the calculator. A stronger number can still be the wrong path.
Methodology
Gross burn is monthly costs. Net burn is monthly costs minus monthly revenue. When net burn is positive and cash on hand is zero or greater, runway is cash ÷ net burn, so zero cash is zero months. Cash that is already negative is not a future runway. Negative net burn means the business is adding cash. Zero net burn has no finite runway.
Assumptions
- The monthly figures repeat until you change them.
- Cash is an optional companion input, not a forecast.
Examples
Partial coverage
$40,000 costs and $15,000 revenue is $40,000 gross burn and $25,000 net burn.
How to use this tool
- Enter monthly costs and monthly revenue.
- Optionally enter cash to see runway at that net burn.
- Read gross burn, net burn, and whether cash is being generated.
Limitations
- One-time expenses need to be averaged into the monthly cost you enter.
- Not financial advice.
Questions
- What is gross burn versus net burn?
- Gross burn is monthly costs. Net burn is costs minus revenue. Net burn is what consumes the bank balance.
- Can burn be negative?
- Yes. If revenue exceeds costs, net burn is negative and the business is adding cash.