How to Calculate Burn Rate (Step-by-Step)
The median seed-stage startup burns $95K/month. Calculate your gross and net burn rate in 4 steps with formulas, worked examples, and 2026 benchmarks by stage.
The median seed-stage startup burns $95K per month in net burn. Series A companies burn $180K-$350K/month. Your burn rate is the single most important number for understanding how long your startup can survive before it either becomes profitable or needs more funding. Miscalculating it -- or ignoring it -- is how startups die.
Burn rate is not complicated, but founders get it wrong more often than you would expect. They confuse gross and net burn, forget to include accrued expenses, or use average burn when their actual spend is accelerating. This guide walks through the calculation step-by-step with real numbers, explains the difference between gross and net burn, and provides benchmarks so you know where you stand.
Step 1: Understand Gross Burn vs. Net Burn
There are two types of burn rate, and they answer different questions.
Gross burn rate is your total monthly cash outflow. It answers: "How much money leaves the bank account each month?" This includes every expense -- payroll, rent, software, marketing, everything.
Net burn rate is your total monthly cash outflow minus your total monthly cash inflow (revenue). It answers: "How much is my cash balance actually decreasing each month?"
Gross Burn = Total Monthly Operating Expenses
Net Burn = Total Monthly Operating Expenses - Total Monthly Revenue
If your startup spends $150K/month and earns $40K/month in revenue:
- Gross burn = $150K/month
- Net burn = $150K - $40K = $110K/month
The distinction matters because it affects how you calculate runway. Gross burn tells you the worst case (if all revenue disappeared). Net burn tells you the current trajectory.
For a detailed breakdown of where startups spend at each stage, see the SaaS burn rate calculator and benchmarks.
Step 2: Gather Your Financial Data
To calculate burn rate accurately, you need three months of financial data at minimum. Using a single month is unreliable because expenses fluctuate (quarterly payments, annual subscriptions, one-time costs).
Collect the following for each of the last three months:
Cash outflows (expenses):
- Payroll (salaries, benefits, payroll taxes)
- Rent and facilities
- Software and tools
- Cloud infrastructure (AWS, GCP, Azure)
- Marketing and advertising spend
- Professional services (legal, accounting)
- Insurance
- Travel and meals
- Any other recurring or one-time expenses
Cash inflows (revenue):
- Subscription revenue collected
- Services revenue collected
- Any other cash received from customers
The key word is "collected." Use cash-basis numbers, not accrual. Burn rate measures actual cash movement, not accounting revenue. If a customer signed a $120K annual contract but pays monthly, count $10K/month as inflow, not $120K in the signing month.
Step 3: Calculate Monthly Burn Rate
Simple Method (3-Month Average)
Take the average of the last three months to smooth out fluctuations.
Average Monthly Gross Burn = (Month 1 Expenses + Month 2 Expenses + Month 3 Expenses) / 3
Average Monthly Net Burn = Average Monthly Gross Burn - Average Monthly Revenue
Worked Example
| January | February | March | Average | |
|---|---|---|---|---|
| Payroll | $72,000 | $72,000 | $78,000 | $74,000 |
| Rent | $8,000 | $8,000 | $8,000 | $8,000 |
| Software/Tools | $4,200 | $4,200 | $4,200 | $4,200 |
| Cloud Infrastructure | $6,800 | $7,100 | $7,400 | $7,100 |
| Marketing | $12,000 | $15,000 | $18,000 | $15,000 |
| Professional Services | $3,000 | $1,500 | $4,500 | $3,000 |
| Other | $2,000 | $2,200 | $1,900 | $2,033 |
| Total Expenses | $108,000 | $110,000 | $122,000 | $113,333 |
| Revenue | $28,000 | $31,000 | $34,000 | $31,000 |
| Net Burn | $80,000 | $79,000 | $88,000 | $82,333 |
Average gross burn = $113,333/month Average net burn = $82,333/month
Notice that both expenses and revenue are trending up. The average smooths this out, but if the trend continues, next month's burn will be higher than the average suggests.
Trend-Adjusted Method
If your expenses are growing (hiring, scaling marketing), the simple average understates your actual burn. Use a weighted average that gives more weight to recent months.
Weighted Average = (Month 1 x 1 + Month 2 x 2 + Month 3 x 3) / 6
Using the net burn numbers above:
Weighted Net Burn = ($80,000 x 1 + $79,000 x 2 + $88,000 x 3) / 6 = ($80,000 + $158,000 + $264,000) / 6 = $83,667/month
The weighted average of $83,667 is slightly higher than the simple average of $82,333, reflecting the upward trend in spending.
Step 4: Calculate Runway
Runway is how many months you can operate at the current burn rate before running out of cash.
Runway (months) = Current Cash Balance / Monthly Net Burn Rate
If your bank balance is $1.2M and your net burn is $82,333/month:
Runway = $1,200,000 / $82,333 = 14.6 months
That is a comfortable runway for a seed-stage company. The general rule is to maintain at least 12-18 months of runway and start fundraising when you have 6-9 months left.
Use a burn rate calculator to model different scenarios: what happens if you hire two more engineers, double marketing spend, or revenue grows 15% per month?
Burn Rate Benchmarks by Stage
Here is what typical burn rates look like across funding stages, based on 2026 data from startup benchmarking reports:
| Stage | Median Gross Burn | Median Net Burn | Team Size | Typical Runway |
|---|---|---|---|---|
| Pre-seed | $30K - $60K | $25K - $55K | 2-4 | 12-18 months |
| Seed | $80K - $150K | $65K - $120K | 5-12 | 15-22 months |
| Series A | $200K - $400K | $150K - $300K | 15-40 | 18-24 months |
| Series B | $500K - $1M | $300K - $700K | 40-100 | 18-30 months |
| Series C+ | $1M - $3M | $500K - $2M | 100-300 | 24-36 months |
For a deeper look at how these numbers break down by sector and geography, see our comprehensive startup runway and burn rate benchmarks by stage.
Burn Rate by Expense Category
Where does the money go? Here is the typical breakdown for a seed-stage SaaS startup:
| Category | % of Total Burn | Monthly Amount (at $100K burn) |
|---|---|---|
| Payroll & Benefits | 65-75% | $65,000 - $75,000 |
| Cloud Infrastructure | 8-12% | $8,000 - $12,000 |
| Software & Tools | 3-5% | $3,000 - $5,000 |
| Marketing & Ads | 5-10% | $5,000 - $10,000 |
| Rent & Facilities | 3-5% | $3,000 - $5,000 |
| Professional Services | 2-4% | $2,000 - $4,000 |
| Other | 2-5% | $2,000 - $5,000 |
Payroll dominates. If you need to cut burn, headcount reductions have the largest impact. Everything else is a rounding error by comparison.
Common Mistakes When Calculating Burn Rate
Mistake 1: Forgetting Accrued but Unpaid Expenses
If you receive an invoice in March but do not pay it until April, your March cash outflow understates the true burn. For burn rate purposes, count expenses when they are incurred, not when the check clears. Otherwise, you will be surprised by a "spike" that was actually a delayed payment.
Mistake 2: Excluding One-Time Costs
Some founders strip out one-time costs (legal fees for a fundraise, security deposit on an office) to calculate "normalized" burn. This is fine for understanding recurring burn, but your cash balance does not care about normalization. Track both normalized and actual burn.
Mistake 3: Using Bookings Instead of Cash Collected
If you signed a $120K annual contract but the customer pays monthly, your cash inflow is $10K/month, not $120K. Using bookings inflates your revenue and understates net burn. This is particularly dangerous for enterprise SaaS companies with long payment terms.
Mistake 4: Ignoring Seasonality
Some expenses are annual (insurance renewal, conference sponsorships) or quarterly (tax payments, performance bonuses). If you only look at months without these payments, your average understates true burn. Include at least 6-12 months of data for an accurate picture.
Mistake 5: Not Tracking Burn Rate Trend
A single burn rate number is less useful than the trend. Is burn increasing or decreasing? Is net burn improving because revenue is growing faster than expenses? Or is gross burn dropping because you made cuts? The direction and the reason matter as much as the absolute number.
When to Cut Burn Rate
Not every increase in burn rate is bad. Increasing burn to invest in growth that pays back within 12-18 months is rational. But here are the signals that you should cut:
Runway below 12 months with no fundraise planned. This is the most obvious trigger. If you are not planning to raise and you have less than 12 months of runway, cut now.
Net burn increasing faster than revenue. If your expenses are growing 15% per month but revenue is growing 5%, the trajectory is unsustainable. The gap will widen every month.
CAC payback exceeding 24 months. If it takes more than two years for a customer to pay back their acquisition cost, your growth spending is inefficient and increasing it will only accelerate cash depletion.
Gross margins declining. If each dollar of revenue costs more to deliver, scaling revenue does not help. Fix the margin problem before spending more on growth.
FAQ
What is the difference between burn rate and runway?
Burn rate is how much cash you spend per month (net of revenue). Runway is how many months of cash you have left at the current burn rate. They are directly related: runway equals your cash balance divided by your monthly net burn rate. A $1M balance with $100K/month net burn gives you 10 months of runway.
Should I use gross burn or net burn for planning?
Use net burn for primary planning because it reflects your actual cash trajectory. Use gross burn as a stress test: if all revenue disappeared tomorrow, how long would your cash last? Early-stage startups with unpredictable revenue should pay more attention to gross burn. Later-stage companies with stable, recurring revenue can rely on net burn.
How often should I recalculate burn rate?
Recalculate monthly using a trailing three-month average. Review the trend quarterly in board meetings. If you are making significant changes to spending (new hires, marketing ramp, cost cuts), recalculate weekly for the first month after the change to ensure the actual impact matches your plan.
Sources
- Kruze Consulting, "2025 Startup Burn Rate Benchmarks" (analysis of 800+ startups)
- First Round Capital, "State of Startups 2025"
- Y Combinator, "Default Alive or Default Dead" (Paul Graham, updated 2024)
- Carta, "State of Private Markets Q4 2025"
- SaaStr, "The Burn Rate vs. Growth Tradeoff in 2025-2026"
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Written by Team culta
The culta.ai team helps businesses track revenue, manage cash flow, and make smarter financial decisions across multiple entities.