If you’re building a SaaS company in cybersecurity or medtech, you’ve heard investors ask: “What’s your burn?” Most founders give one number. Sophisticated operators know there are two — and confusing them is one of the most costly mistakes you can make in a board meeting or a fundraise.
| Key Takeaway Gross burn tells you how much you spend. Net burn tells you how fast you’re running out of money. Both metrics are essential, and the one you emphasize depends entirely on your stage of growth. |
The Two Burn Rate Metrics Defined
| Gross Burn Rate Total Monthly Operating Expenses All cash going out the door each month — payroll, cloud infrastructure, R&D, compliance costs, G&A. Revenue is not a factor. This is your total cost structure. | Net Burn Rate Gross Burn minus Revenue Collected The actual monthly reduction in your cash balance after accounting for revenue. This is what shortens your runway and drives your next fundraise timeline. |
A practical example: your SaaS company spends $300,000/month in operating expenses and collects $120,000 in monthly recurring revenue. Your gross burn is $300K. Your net burn is $180K. The difference matters enormously for how long your current cash will last.
Why Cybersecurity and MedTech Are Different
Both sectors carry cost structures that are fundamentally heavier than typical B2B SaaS. In cybersecurity, threat research, SOC infrastructure, and compliance overhead (SOC 2, FedRAMP, ISO 27001) drive gross burn higher before you sign a single enterprise contract. In medtech SaaS, FDA regulatory pathways, HIPAA compliance infrastructure, and clinical validation cycles mean you can be burning at growth-stage levels while still in pre-revenue or early-revenue territory.
This is precisely why tracking gross burn separately gives you — and your investors — a clear picture of your true cost model, independent of where you are in the revenue ramp.
How Burn Rate Applies at Each Stage of Growth
| Stage | Primary Metric | What to Watch | CPA Insight |
| Pre-Revenue | Gross Burn | Gross burn = net burn. Every dollar out is unrecovered. Monitor runway in months obsessively. | Keep a 13-week cash flow forecast updated weekly. Categorize expenses by necessity vs. growth investment. |
| Early Revenue ($0–$1M ARR) | Both | Net burn should be declining even if gross burn is flat or rising. Revenue coverage ratio is the leading indicator. | Use accrual-basis gross burn for cost control; use cash-basis net burn for runway. Do not mix the two. |
| Growth Stage ($1M–$10M ARR) | Net Burn | Gross burn may spike with hiring and GTM investment. Net burn is how investors measure capital efficiency and path to break-even. | Model net burn at multiple ARR growth scenarios. Investors want to see net burn declining as a % of ARR. |
| Scaling ($10M+ ARR) | Net Burn / FCF | Transition focus from net burn to free cash flow. Gross burn discipline ensures you can sustain investment while approaching profitability. | Introduce Rule of 40 analysis alongside burn metrics. Gross burn becomes a lever for margin expansion. |
Common Mistakes Founders Make
- Reporting only net burn to investors, which can mask an unsustainable cost structure when revenue is lumpy or contract-driven — common in enterprise cybersecurity deals.
- Including deferred revenue in net burn calculations. Revenue collected ≠ revenue earned. Use cash receipts, not recognized revenue, for burn calculations.
- Ignoring gross burn during hypergrowth. If you’re hiring aggressively and gross burn is rising faster than net burn is falling, you’re building in fragility against a revenue miss.
- Failing to separate one-time capital expenditures from recurring operating burn. For medtech SaaS, regulatory consulting and clinical data costs can distort your normalized gross burn picture.
The Practical Framework: Know Both Numbers Every Month
At a minimum, your monthly financial close should produce three burn-related outputs: gross burn by cost category, net burn versus prior month, and updated runway in months based on current cash balance. For companies in regulated sectors, layer in a compliance cost sub-total within gross burn — this gives you a cleaner view of your operational leverage as you scale.
If your net burn is declining but your gross burn is rising, that is a healthy sign — you are scaling efficiently. If both are rising at similar rates, your revenue growth is not yet covering new investment. If gross burn drops but net burn holds, something is wrong with collections or your revenue model.
Bottom Line
Gross burn and net burn are not interchangeable. Gross burn is a management tool — it tells you where the money goes and where to optimize. Net burn is a survival metric — it tells you how long you have and what the next 12 months need to look like. The best SaaS founders in cybersecurity and medtech use both, in tandem, at every stage.
If your monthly financial reporting doesn’t clearly separate these two figures, that is the first thing to fix — before your next board meeting, and certainly before your next raise.
| Questions about structuring your financial reporting or preparing for a fundraise? Reach out for a consultation —robin.herod@herod.cpa |