How to calculate burn rate starts with tracking cash over a month and understanding what changed. Once you know your monthly net burn, you can estimate how long your current cash may last.
What does burn rate tell you about your startup?
Burn rate describes how quickly a company uses cash. It is useful for planning because it connects your spending and revenue to the time you have to operate and reach business milestones.
Two measures are important:
- Gross burn is the company’s total monthly operating spending.
- Net burn is gross burn minus monthly revenue. It shows how much cash the company loses from operations after revenue is counted.
These figures answer different questions. Gross burn shows the full monthly cost of operating. Net burn shows how much of that cost is not covered by revenue. When investors ask about burn, they usually mean net burn, so label the number you share and be prepared to explain both.
A burn figure is more informative when you can describe what it supports. Spending that contributes to growth or progress toward a milestone can have a different meaning from spending that rises while key metrics remain flat. The number alone does not explain whether your current pace is sustainable or productive.
How do you calculate burn rate each month?
One way to estimate monthly net burn is to compare the company’s cash at the beginning and end of the month:
Monthly net burn = starting cash - ending cash
For example, if your company starts March with $500,000 and ends the month with $450,000, the difference is $50,000. That indicates $50,000 of net burn over the month if the change reflects operating cash use.
You can also calculate the operating measures directly:
- Gross burn = total monthly operating expenses
- Net burn = gross burn - monthly revenue
For example, if monthly spending is $80,000 and monthly revenue is $30,000, monthly net burn is $50,000. Revenue reduces the amount of cash operations consume.
The cash-balance comparison is a practical check, but it does not explain every movement in cash. Look at spending and revenue as well, so you understand what drove the change. Keep gross and net figures distinct when you review or communicate them. That makes it easier to explain whether a change came from operating costs, revenue, or another cash movement.
How do you estimate runway from burn rate?
Runway is an estimate of how many months the company can keep operating at its current net burn before cash runs out. Use this formula:
Runway in months = current cash / monthly net burn
If your company has $600,000 in cash and net burn is $50,000 a month, the estimate is 12 months of runway.
Treat that result as a planning estimate, not a guaranteed endpoint. Hiring, revenue growth, spending changes, or other shifts in the business can change your burn and therefore your runway. Recalculate monthly, and revisit the estimate whenever cash, revenue, or expenses change. Regular reviews can help you see whether the available time is increasing or shrinking while there is still room to plan.
What do investors consider when they review burn?
Investors consider burn in relation to progress rather than treating one dollar amount as automatically good or bad. High spending may be easier to justify when it accompanies fast growth. High burn alongside flat metrics can raise concerns. Be ready to explain what the cash is funding and how that supports the next milestone.
At the growth stage, investors may also examine the burn multiple:
Burn multiple = net burn / net new ARR
A burn multiple below 1.5x, and ideally below 1x, indicates that the company is spending less than a dollar in net burn to add a dollar of recurring revenue. It is one way to consider efficiency, not a replacement for understanding the company’s situation.
Runway and the operating plan behind it matter, too. The company should aim for at least 12 months of runway after a raise, ideally 18 to 24 months, to provide time to reach its next milestone. A fundraising round takes three to six months to close. Starting when roughly six months of runway remain can give you time to work through the process.
Prepare to explain your net burn, cash on hand, runway, and the measurable progress your spending is intended to produce. Confidence in the calculation matters, but so does a clear account of the assumptions behind it.
Which burn rate mistakes should founders avoid?
- Mixing up gross and net burn. Gross burn is total monthly spending; net burn subtracts revenue. State clearly which measure you are using.
- Assuming runway will stay the same. The estimate depends on current cash and net burn. Update it monthly as the business changes.
- Discussing burn without explaining progress. Context helps investors assess what spending is achieving and whether the company is advancing toward milestones.
- Waiting until cash is nearly gone to plan a raise. Use runway to inform your fundraising timeline. A round takes time to close.
- Cutting costs without weighing momentum. Spending that supports strong growth may serve a different purpose from spending that rises while metrics stay flat. Consider what the spend produces before deciding how to respond.
How Round Funded helps founders plan fundraising
- Submit your startup on Round Funded to get matched with investors. Submit your startup on Round Funded and use your runway plan to inform when you prepare to raise.
- Search a database covering 60,000+ active VCs, angels, family offices, and accelerators. Get matched with active investors. Filter by stage, industry, geography, and check size.
- Use AI to draft personalized outreach emails and follow-ups for each investor. Submit your startup on Round Funded to get matched with investors. Outreach goes from your own Gmail, so replies land in your inbox and the thread belongs to you.
- Build and share a Data Room with your deck, traction, team, and ask on one link. It is free to build and share on every plan.
- Keep investors, fundraising stages, and next steps together in the fundraising pipeline. Round+ includes per-investor tracked links and engagement analytics, including views, deck opens, and meeting clicks.
Frequently Asked Questions
What is the difference between gross burn and net burn?
Gross burn is total monthly operating spending. Net burn subtracts monthly revenue from that spending, showing how much cash operations consume after revenue.
How do you calculate monthly net burn?
Subtract ending cash from starting cash for a cash-based monthly estimate, provided the change reflects operating cash use. You can also subtract monthly revenue from total monthly operating expenses to calculate net burn directly.
How do you calculate startup runway?
Divide current cash by monthly net burn. For example, $600,000 in cash divided by $50,000 of monthly net burn gives 12 months of runway. Recalculate when cash, revenue, or spending changes.
What is a good burn rate for a startup?
There is no single figure that works for every company. Consider burn alongside progress, revenue, and the milestones your spending is intended to support.
When should a startup start fundraising?
A round takes three to six months to close, so starting when roughly six months of runway remain can leave time to work through the process. After raising, aim for at least 12 months of runway, ideally 18 to 24 months.