Net Burn

What is net burn?

Net burn (also called net burn rate, net cash consumption, or net monthly cash depletion) is the amount of cash a company actually loses each month after accounting for revenue collected. It is calculated by subtracting cash received from customers in a month from total cash outflows in that same month. Net burn is the definitive metric for runway calculation — it shows the real rate at which cash reserves are being depleted.

Net burn is distinct from gross burn in one critical way: revenue. Gross burn is what the business costs to run. Net burn is what the business actually drains from cash reserves after revenue offsets some of those costs. For pre-revenue companies, both numbers are the same. For a company with $240K gross burn and $95K in monthly cash receipts, net burn is $145K — and that is the number that determines how many months of operation remain.

The most common error in net burn calculation is using ARR/12 or MRR as the revenue figure instead of actual cash collected. For companies with annual contracts paid upfront, ARR/12 understates cash receipts in the collection month and overstates them in subsequent months. For companies with net-30 payment terms, ARR/12 overstates the actual cash available. Net burn must use cash basis revenue — not accounting-based revenue recognition.

Net burn is also what investors and board members use to assess fundraise timing. A company with 14 months of runway at current net burn has time to run a deliberate fundraise process. A company with 7 months does not. The specific net burn number — not just whether the company is "burning cash" — determines the urgency and terms of the next capital raise.

Why net burn matters for operators

The cost of not tracking net burn precisely is compression of the decision window. A company that calculates net burn from accurate monthly data can project fundraise timing 9-12 months in advance and initiate the process with optionality. A company that estimates burn loosely — rounding to the nearest $50K, using last quarter's average — discovers the same constraint with 4-5 months of runway instead of 12. The fundraise that takes 5-6 months from first meeting to cash-in-bank is now impossible to complete before running out of money.

Net burn is also the metric that most directly connects to the burn multiple — the capital efficiency ratio that investors increasingly use to evaluate pre-profitability companies. Burn multiple = net burn / net new ARR added in the month. A company with $150K net burn adding $60K of new ARR has a 2.5x burn multiple, which is poor. The same net burn adding $180K of ARR produces a 0.83x burn multiple, which is excellent. You cannot assess capital efficiency without an accurate net burn figure.

For CFOs managing fundraise timing, net burn trend matters as much as the absolute number. A company where net burn grew from $90K to $160K over 90 days while MRR grew $12K has a widening gap that will compress runway faster than the current snapshot suggests. Static net burn figures mislead. Trend-based net burn analysis reveals the actual trajectory.

Net burn formula

Net Burn = Gross Burn - Revenue Collected (cash receipts, not ARR/12)

Alternate method:
Net Burn = (Beginning Cash Balance - Ending Cash Balance) / Months

Example (cash receipts method):
  Gross burn:              $230,000
  Cash collected:          $85,000
  Net burn:                $145,000

Example (bank balance method):
  Cash on Jan 1:           $2,100,000
  Cash on Mar 31:          $1,668,000
  3-month net burn:        $432,000
  Monthly net burn:        $432,000 / 3 = $144,000

Cash-flow neutral = Net Burn of $0
Cash-flow positive = Negative Net Burn (profitable on cash basis)

• Gross burn — all cash outflows (payroll, rent, software, marketing, COGS, all OpEx)
• Revenue collected — actual bank deposits from customers; not invoiced, not recognized
• Exclude deferred revenue — annual contracts paid upfront inflate the collection month
• Exclude one-time revenue — asset sales, grants, non-recurring items distort the baseline
• Normalize for billing cycles — monthly, annual, and quarterly contracts hit bank at different times
• Use 3-month rolling average for stable net burn calculation that smooths timing anomalies

Net burn benchmarks by stage

Net burn benchmarks are most meaningful when expressed relative to ARR growth (burn multiple). Absolute ranges provide a rough check; the ratio to growth is the quality signal.

Sources: David Sacks / Craft Ventures burn multiple framework (2022, widely adopted); a16z SaaS benchmarks; Bessemer Venture Partners State of the Cloud 2025. Burn multiple thresholds are industry norms, not hard rules — growth rate, market size, and competitive position all affect what investors will accept.

Common mistakes when calculating net burn

1. Using ARR/12 instead of actual cash collections

This is the most consequential calculation error in startup finance. ARR/12 is a smoothed theoretical average. Actual cash collected in a given month depends on billing cycles, payment timing, new logo closings, and annual contract renewals. A company that closes two large annual contracts in October will show 3-4x more cash receipts in October than ARR/12 predicts — and then have near-zero incremental receipts for the following 11 months. Net burn calculated on ARR/12 is wrong in both directions every month.

2. Including deferred revenue as collected revenue

When a customer pays an annual contract upfront, the full cash is received but only 1/12 is recognized as revenue in month one. Net burn should use cash collected, not revenue recognized. However, teams that use accounting-system revenue figures accidentally exclude upfront payments (because they're deferred) and overstate net burn in the collection month. Use the bank statement, not the revenue recognition schedule.

3. Not adjusting for one-time revenue spikes

A professional services project that generates $80K in a single month, or a customer who pays two years of subscription upfront, will suppress net burn dramatically in that month. Using that month's net burn as a forward baseline produces an overly optimistic runway projection. Flag one-time revenue receipts separately and calculate a normalized net burn baseline that excludes non-recurring cash inflows.

4. Confusing net burn with burn multiple

Net burn is an absolute dollar amount — how much cash depleted this month. Burn multiple is a ratio — net burn divided by new ARR added. They measure different things. A company can have a low net burn but a terrible burn multiple (barely adding ARR). They can also have a high net burn but an excellent burn multiple (growing ARR rapidly). Both metrics are necessary; neither substitutes for the other.

5. Not tracking month-over-month net burn trend

A single net burn number tells you where you are. A 90-day trend in net burn tells you where you are going. A company with $140K net burn that ran at $90K three months ago has a materially different outlook than one that ran at $190K. The trend — not the point-in-time figure — is what determines whether runway is expanding or contracting. Calculate net burn every month, retain the history, and report the trend alongside the current figure.

How Fairview tracks net burn automatically

Fairview's Operating Dashboard calculates net burn from actual cash data — Stripe cash receipts, QuickBooks or Xero cash outflows — rather than from accounting estimates or ARR/12 approximations. Annual contracts are tagged when collected so their one-time nature is visible in the data. The dashboard shows net burn by month, with a 3-month rolling average and trend direction, updated automatically as new transactions clear.

When net burn trend diverges from ARR growth — specifically when net burn rises while MRR growth is flat or declining — Fairview's Next-Best Action Engine triggers a capital efficiency alert: "Net burn increased from $94K to $151K over 90 days while MRR grew only $8K. Net burn is now 2.1x new ARR added. At this trajectory, runway compresses from 18 months to 9 months in 6 months." The alert quantifies the burn multiple change, projects the runway compression, and recommends a specific review timeline.

→ See how the Operating Dashboard works

Net burn vs burn multiple

Net burn is the absolute monthly cash depletion figure. Burn multiple is the capital efficiency ratio that contextualizes net burn against growth. Both are necessary. Net burn tells you how long you can last. Burn multiple tells you whether you're spending efficiently. Use net burn for runway projections and fundraise timing; use burn multiple for board conversations and investor due diligence.

Frequently asked questions

Sources

1. a16z: How to Think About Burn Rate
2. Bessemer Venture Partners State of the Cloud 2025