The speed of monthly cash consumption — gross (all spending) or net (spending minus cash revenue).

How is runway calculated?

Cash on hand divided by net monthly burn — the months until the account hits zero at current trajectory.

What does burn rate mean for marketing?

It sets payback discipline — the shorter the runway, the shorter the acceptable CAC payback on any spend.

Growth Marketing Glossary

Burn Rate

burn rate/bəɹn ɹeɪt/noun

Every startup is a fire consuming cash — this is the reading on the fuel gauge.

Schematic — monthly cash out exceeding cash in

Term: Burn Rate
Forms: Gross burn / net burn
Unit: Currency / month
Companion: Runway = cash ÷ net burn

Forms & parts of speech

burn · noun (clipped form)

Monthly net cash consumption.

"Our burn is $400k against fourteen months of runway — the rebrand can wait."

Definition in plain terms

Burn rate is how fast a company consumes cash, stated monthly. GROSS burn is total monthly cash spending; NET burn is spending minus cash revenue — the number that matters, because it's what actually drains the account. A company holding $4.2M with a net burn of $300k/month has fourteen months of runway: the burn rate's whole purpose is that division.

The mechanics

Burn is a cash-flow concept, not an accounting one — count cash out the door, not accrued expenses, and watch the items P&Ls smooth over (annual contracts paid up front, payroll timing). Net burn falls two ways: cut spending or grow revenue, and the second compounds while the first usually can't repeat. For marketers, burn context sets the rules of engagement — at high burn, experiments need short payback windows; CAC payback time stops being a finance nicety and becomes survival math.

When it matters

Burn matters always but rules during fundraising gaps and downturns — the 'default alive or default dead' question is burn versus growth trajectory. Marketing sits in burn's blast radius: brand spend with 18-month payoffs is rational at 30 months of runway and reckless at 8. The healthiest discipline is pricing every marketing program in runway-months — it converts budget debates into the one currency founders actually spend.

Worked example. A Series A startup with 11 months of runway debates a $600k brand campaign with an estimated 14-month payback. Priced in burn terms, the campaign costs two runway-months for a payoff arriving after the company would be dead without a raise. The marketing lead reframes the plan: performance spend with sub-4-month payback now, the brand program staged to begin the week a term sheet clears. Same total budget across two years — sequenced by the fuel gauge instead of the calendar.

Failure modes to watch. Confusing gross with net burn in runway math; treating burn as fixed while revenue is the lever; running long-payback marketing at short runway; and discovering the real burn from the bank balance instead of the model.

Synonyms & antonyms

Synonyms

burn ratecash burnmonthly burn

Antonyms

cash-flow positiveprofitability

Origin & history

*Reconstructed from language history and industry usage; no single verifiable origin source exists. 'Burn rate' originates in aerospace engineering — the consumption rate of rocket propellant — and crossed into venture finance as a metaphor for cash consumption, entering common startup vocabulary by the late 1980s and becoming ubiquitous (with books titled for it) in the dot-com era.

Etymology: source.

Usage trends

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Common questions

What is burn rate?: The speed of monthly cash consumption — gross (all spending) or net (spending minus cash revenue).
How is runway calculated?: Cash on hand divided by net monthly burn — the months until the account hits zero at current trajectory.
What does burn rate mean for marketing?: It sets payback discipline — the shorter the runway, the shorter the acceptable CAC payback on any spend.