OmniCalc

Burn Rate

Business

Calculate monthly burn rate

Burn rate measures how fast a company spends cash — and for any business not yet profitable, especially venture-backed startups, it is the single most important number for survival planning. Run out of cash before reaching profitability or the next funding round, and the business fails, regardless of how good the product or growth metrics look.

There are two versions of burn rate. Gross burn rate is simply total monthly operating expenses — every dollar going out the door. Net burn rate subtracts monthly revenue from expenses, showing the actual net cash outflow. Net burn rate is the more useful number for most planning purposes, because it reflects what's really draining the bank account after revenue is accounted for.

Our burn rate calculator takes your monthly expenses, monthly revenue, and current cash balance, then instantly returns your gross burn, net burn, and — most critically — your runway: how many months of operation remain at the current burn rate before the company runs out of cash. This is the number founders bring to board meetings, use to time fundraising, and rely on to decide when to cut costs or accelerate growth.

Why Burn Rate Matters

Runway is the clock every startup operates against. Knowing precisely how many months of cash remain determines when a founder must start fundraising (typically 6-9 months before running out, since raises take longer than expected), when to make hiring decisions, and when cost discipline needs to tighten. Founders who don't track burn rate closely are frequently blindsided by a cash crunch that a simple monthly calculation would have flagged months in advance.

Investors scrutinize burn rate as a proxy for capital efficiency and management discipline. Two companies with identical revenue growth can look very different to an investor if one burns $50,000/month to get there and the other burns $500,000/month — the former is a far more capital-efficient, and generally more fundable, business. Burn rate also directly affects valuation conversations: a company burning cash fast with a short runway has much less negotiating leverage in a fundraise than one with 18+ months of runway.

Beyond fundraising, burn rate discipline shapes day-to-day operating decisions: whether to make a new hire, whether to invest in a marketing campaign, or whether to pursue a larger office lease. Every one of these decisions changes monthly expenses, which changes net burn, which changes runway — a chain that founders and finance teams should model before committing to major spending.

The Burn Rate Formula, Explained

Gross Burn Rate = Total Monthly Operating Expenses; Net Burn Rate = Monthly Expenses − Monthly Revenue; Runway (months) = Cash Balance / Net Burn Rate

Gross burn rate is the simplest figure: add up everything the company spends in a month — salaries, rent, software, marketing, and all other operating costs. It represents total cash outflow regardless of any revenue coming in.

Net burn rate subtracts monthly revenue from monthly expenses, showing the actual net drain on the bank account. If a company spends $180,000/month and brings in $65,000/month in revenue, its net burn is $115,000/month — the number that actually determines how fast cash reserves are shrinking. If monthly revenue exceeds monthly expenses, net burn is negative, meaning the company is actually cash-flow positive and not burning cash at all.

Runway divides the current cash balance by net burn rate, producing the number of months the company can continue operating at its current pace before running out of money. A company with $1,150,000 in the bank and $115,000/month net burn has 10 months of runway — a figure that should trigger fundraising or cost-cutting conversations well before it approaches zero.

How to Use the Burn Rate: Step by Step

  1. List monthly operating expenses

    Total every recurring monthly cost: payroll, rent, software subscriptions, marketing, contractor fees, and any other operating expense. This total is your gross burn rate.

  2. Add monthly revenue

    Input your average monthly revenue. If revenue is inconsistent, use a trailing 3-month average for a more stable figure.

  3. Calculate net burn

    The calculator subtracts revenue from expenses to find net burn rate — the real monthly cash outflow the business needs to plan around.

  4. Enter current cash balance

    Input the company's current cash on hand (bank balance), which the calculator divides by net burn to find runway.

  5. Review runway and plan ahead

    Use the resulting runway figure to time fundraising efforts (start 6-9 months before cash runs out), evaluate hiring plans, or identify where costs need to be cut.

Burn Rate Examples: Real-World Scenarios

1

Early-Stage Startup with Some Revenue

A seed-stage startup spends $180,000/month on payroll, tools, and rent, and generates $65,000/month in revenue. It has $1,150,000 in the bank.

Monthly expenses:$180,000
Monthly revenue:$65,000
Cash balance:$1,150,000

Calculation

Net burn = 180,000 − 65,000 = 115,000. Runway = 1,150,000 / 115,000 = 10.0 months

Result

The company has 10 months of runway at its current burn rate — meaning fundraising conversations should begin within the next 1-4 months to leave adequate lead time before cash runs out.

2

Pre-Revenue Startup — Gross Burn Equals Net Burn

A pre-revenue startup spends $90,000/month with no revenue yet, and has $450,000 in the bank.

Monthly expenses:$90,000
Monthly revenue:$0
Cash balance:$450,000

Calculation

Net burn = 90,000 − 0 = 90,000 (equal to gross burn). Runway = 450,000 / 90,000 = 5.0 months

Result

With no revenue offsetting expenses, the company has just 5 months of runway — an urgent signal to either raise capital immediately, cut costs, or accelerate toward first revenue.

3

Growing Company Extending Runway by Cutting Costs

A startup currently spends $250,000/month with $95,000/month in revenue and $600,000 in the bank. Leadership is considering a cost cut to extend runway.

Monthly expenses:$250,000
Monthly revenue:$95,000
Cash balance:$600,000

Calculation

Current net burn = 250,000 − 95,000 = 155,000. Current runway = 600,000 / 155,000 ≈ 3.87 months

Result

At the current pace, runway is only about 3.9 months — a critical warning sign. Cutting monthly expenses by $50,000 (to $200,000) would reduce net burn to $105,000 and extend runway to about 5.7 months, buying crucial extra time.

Common Mistakes to Avoid

  • Using gross burn instead of net burn for runway calculations, which understates how long the company can actually survive if there's meaningful revenue offsetting expenses.
  • Calculating burn rate from a single unusually high or low month rather than a trailing 3-6 month average, which can produce a misleadingly optimistic or pessimistic runway figure.
  • Ignoring irregular but predictable large expenses (annual insurance premiums, quarterly tax payments) that don't show up in a typical month's operating costs but will hit the bank account eventually.
  • Waiting too long to start fundraising because runway looked comfortable — most raises take 3-6 months from first pitch to funds in the bank, so founders should start well before runway gets short.

Tips & Tricks

  • As a general rule, start fundraising when you have at least 6-9 months of runway remaining — raises routinely take longer than founders expect, and running out of leverage during negotiations is costly.
  • Recalculate burn rate and runway monthly, not just when preparing for a board meeting — expenses and revenue can shift quickly, especially after a new hire or a big new customer contract.
  • Model runway under multiple scenarios (current pace, a hiring freeze, a 20% cost cut) so you have a concrete, pre-planned response ready if runway shortens unexpectedly.

Burn rate and runway are the clock every early-stage company is racing against, and tracking them closely is one of the simplest, highest-leverage habits a founder can build. Gross burn shows total spend, net burn shows the real cash drain after revenue, and runway converts that into the number of months left to operate, raise, or reach profitability. Pair this calculator with our revenue calculator and CAGR calculator to connect your burn rate to the growth trajectory that will ultimately need to outrun it.

Burn Rate — Frequently Asked Questions

Related Calculators

Revenue Calculator

project the revenue that offsets your burn rate

Break-Even Calculator

find out when revenue will cover your expenses

CAGR Calculator

check whether your growth rate can outrun your burn

Customer Lifetime Value Calculator

see how customer economics affect your cash runway

ROI Calculator

evaluate whether spending is generating adequate returns

Authoritative References

Y Combinator — Default Alive or Default Dead

ycombinator.com — Foundational startup guidance on burn rate and runway planning

U.S. Small Business Administration — Manage Your Finances

sba.gov — Official guidance on cash flow and expense management

Investopedia — Burn Rate Definition

investopedia.com — Formula reference and startup finance context

External links open in a new tab. OmniCalc.us is not affiliated with these organisations.

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