Business Runway: How Long Will Your Money Last?

Business runway is how many months your business can operate before running out of cash, calculated as:

Runway (months) = Current Cash Balance ÷ Net Monthly Burn Rate

Where Net Monthly Burn Rate = Total Monthly Expenses − Monthly Revenue.

If you have $120,000 in the bank and spend $15,000/month while bringing in $5,000/month, your net burn is $10,000/month and your runway is 12 months. The three actions that extend runway are: reduce burn rate, increase revenue, or raise additional capital.

How to calculate business runway

Add up every dollar that left your business bank account last month (gross burn), subtract every dollar that came in (revenue received, not just invoiced), and divide your current cash balance by the difference:

1. Find your ending cash balance — the sum of all business checking and savings account balances today.
2. Calculate gross burn rate — total cash paid out last month across payroll, rent, software, contractors, and all other expenses.
3. Calculate net burn rate — subtract revenue actually received last month (cash collected, not revenue earned but unpaid) from gross burn.
4. Divide cash by net burn — the result is runway in months.

Recalculate on the first of every month. A single number that trends in the wrong direction for two consecutive months warrants immediate action.

Burn Rate and Runway — The Core Calculations

Two burn rate concepts drive every runway calculation:

Gross burn rate is total cash spent per month, regardless of revenue.

• $15,000/month in salaries
• $3,000 rent
• $2,000 software subscriptions
• $1,000 miscellaneous expenses
• Gross burn: $21,000/month

Net burn rate is cash spent minus cash received:

• Gross burn: $21,000
• Revenue received: $8,000/month
• Net burn: $13,000/month
• Runway: $120,000 ÷ $13,000 = 9.2 months

Why the distinction matters: A business with $21,000 gross burn and $20,000 revenue has a net burn of $1,000/month — 120 months of runway on $120,000. The same business with $5,000 revenue has 8.7 months. Same gross burn, radically different survival window. Gross burn tells you your cost structure. Net burn tells you your clock.

What Counts as Cash in Your Runway Calculation

Only count immediately accessible cash. Overstating cash delays hard decisions that should happen sooner.

Include:

• Business checking account balance
• Business savings or money market accounts
• Committed but undrawn credit line — treat as emergency only, not operating cash; include at your discretion
• Accounts receivable due within 30 days at 80% — some will not collect on time, so apply a 20% haircut

Do not include:

• Receivables over 60 days old — collection risk is too high to count
• Inventory — illiquid and uncertain in value
• Equipment or fixed assets — not liquid
• Personal funds you "could" inject — not committed, not countable

A business that counts $40,000 in equipment and $30,000 in slow-paying receivables as runway cash is operating on a false sense of security. When the bank account runs low at month 8, the equipment cannot be converted to payroll within a week.

The Three-Tier Burn Rate Audit

Before making cuts, categorize every expense into one of three tiers:

Tier 1 — Revenue-generating (do not cut):

• Sales and marketing spend with measurable ROI
• Customer success roles that directly drive retention
• Tools that are required to deliver to clients

Tier 2 — Essential operations (minimize, do not eliminate):

• Core infrastructure — hosting, payments processing, accounting software
• Legal and compliance minimums required by contract or law
• Insurance required by contracts or law

Tier 3 — Nice-to-have (cut first, within 30 days):

• Unused or underused SaaS subscriptions
• Office perks and non-essential services
• Conferences and travel above minimum viable attendance
• Contractors performing non-essential work

A typical burn rate audit identifies 15–30% of expenses in Tier 3 that can be cut within 30 days with minimal business impact. For a $21,000/month gross burn, this means $3,150–$6,300 in monthly savings — extending runway by 2–5 months without touching a single revenue-generating activity.

Healthy Burn Rate Benchmarks by Stage

The 18-month rule: Most financial advisors and investors consider 18 months of runway the minimum comfortable threshold. Below 12 months, immediate action is required. Below 6 months, every business decision must be made through the single lens of runway extension — nothing else matters until you fix the clock.

The Six Runway Extension Strategies

These are ordered by speed of impact — fastest results first.

Strategy 1 — Emergency expense audit (implement within 48 hours)

Cancel every non-essential recurring subscription and service. Target: $2,000–$5,000/month savings within one week. Common finds: duplicate SaaS tools ($200–$500/month), unused CRM seats ($100–$300/month per user), redundant communication platforms, and software trials that auto-converted to paid. This step takes 2–4 hours and has zero impact on revenue.

Strategy 2 — Defer non-essential hiring

If a hire was planned but not essential to current revenue generation, defer it. A $80,000/year employee adds $6,700/month to gross burn, plus benefits, payroll taxes, and onboarding overhead — total impact is typically $8,000–$9,000/month all-in. Deferring one planned hire for three months extends runway by 0.9 months for every month deferred on a $120,000 cash base with $13,000 net burn.

Strategy 3 — Accelerate receivables

Invoice immediately on project completion. Offer a 2% early payment discount for payment within 10 days (net 30 terms). For $30,000 in outstanding receivables, accelerating 50% collection brings $15,000 into the business within two weeks — effectively adding one month of runway at $13,000 net burn. Follow up on every invoice over 15 days old with a direct phone call, not an email.

Strategy 4 — Reduce contractor costs

Contractors are often the first to reduce in a burn rate crisis because there is no severance, no HR complexity, and relationships can often be paused and resumed when conditions improve. If contractors represent 20% of gross burn ($4,200/month in the $21,000 example), reducing to essential-only contractors adds 2–3 months of runway without permanently losing the working relationship.

Strategy 5 — Revenue acceleration

Short-term tactics with the fastest cash impact: offer a 10–15% discount for annual prepayment on monthly plans (immediate cash in), launch a one-time service or consulting offering to existing clients, and accelerate closing on pipeline opportunities with time-limited pricing incentives. Revenue acceleration is only viable with runway of 6+ months. Below that, cost conservation is more predictable and reliable — do not gamble runway on uncertain revenue.

Strategy 6 — Raise capital or secure credit

An SBA line of credit, invoice factoring arrangement, or outside equity round takes 30–90 days minimum to arrange. If runway is below 6 months, start this process immediately — do not wait. Credit becomes unavailable precisely when you need it most: lenders see the desperation in your financials and either decline or impose predatory terms. Apply at 12 months of runway when you are a creditworthy borrower negotiating from a position of strength.

The Burn Rate Dashboard — What to Track Monthly

Pull these five numbers on the first of every month, from your accounting software or bank statements:

1. Ending cash balance — total in all business accounts at month close
2. Gross burn rate — total expenses paid last month, from every category
3. Net burn rate — gross burn minus revenue actually received (cash in bank, not revenue earned but unpaid)
4. Runway — current cash divided by net burn rate
5. Burn rate trend — month-over-month change in net burn, as a percentage

The trend is the early warning system. A net burn increasing 5% month-over-month in a growth business is expected and manageable. A net burn increasing 20% month-over-month with runway under 12 months requires immediate intervention — the business is accelerating toward a cliff.

The 12/6/3 rule:

• At 12 months runway: begin exploring all options — fundraising, a line of credit, cost reduction planning. No urgency, but start conversations now.
• At 6 months runway: implement cost reductions immediately. Begin active fundraising or revenue acceleration. This is the last comfortable moment to act.
• At 3 months runway: crisis mode. Cut to the minimum viable burn rate. Pause all non-essential activities. Make the hard personnel decisions that should have happened at 6 months. Every week of delay costs negotiating leverage.

Most business failures trace back to a founder who saw the 6-month warning and chose optimism over action. The 12/6/3 rule is a framework for overriding that instinct with a predetermined decision tree.

Burn Rate for Freelancers and Solopreneurs

Most burn rate guides focus on funded startups with investors and payroll. Freelancers and solopreneurs have a simpler calculation but the same life-or-death financial stakes.

Personal monthly burn rate example:

• Fixed personal expenses (rent, food, insurance, utilities, debt minimums): $3,500/month
• Business fixed costs (software, professional memberships, accounting): $500/month
• Total monthly burn: $4,000/month

Revenue scenarios:

• Average monthly billings: $7,000 at 90% collection rate = $6,300 received → $2,300/month surplus → building runway
• One major client churns: $3,000 revenue → net position: −$1,000/month → on $120K savings: 120 months runway. Survivable.
• All clients churn simultaneously: −$4,000/month net burn → on $120K savings: 30 months runway. Time to find new clients, not panic.

For solopreneurs, the key metric is: what is my monthly personal burn rate, and how many months does my emergency fund cover? The standard recommendation is 6 months of personal burn rate in liquid savings — a freelancer's equivalent of corporate runway. On $4,000/month burn, that means $24,000 in a savings account before any client work begins or continues at risk.

The other critical number for freelancers: your minimum viable client load— the fewest clients needed to cover burn rate with zero surplus. Know this number. It tells you exactly when to panic versus when to simply hustle.

Key Takeaways

• Runway = Current Cash ÷ Net Monthly Burn Rate; net burn = gross expenses minus revenue actually received in cash — not invoiced, not earned, but collected.
• Only count immediately accessible cash (checking, savings, 30-day receivables at 80%) — not inventory, equipment, or personal funds you "could" inject. Overstating cash delays the hard decisions that should happen sooner.
• The 12/6/3 rule: start planning at 12 months of runway, implement cuts at 6 months, enter full crisis mode at 3 months. Most business failures happen because founders saw the 6-month warning and chose optimism over action.
• A typical expense audit finds 15–30% of costs in the Tier 3 nice-to-have category that can be cut within 30 days with zero impact on revenue — often $3,000–$6,000/month in savings on a $20K gross burn base.
• Never apply for credit when you are at 3 months runway — lenders see the crisis in your financials and decline or impose punishing terms. Apply at 12 months when you are a creditworthy borrower with time to walk away from bad offers.

Calculate Your Business Runway

Frequently Asked Questions

What is a good burn rate for a startup?

It depends on stage and revenue. Pre-revenue startups should aim for gross burn under $10,000/month unless they have 24+ months of runway. At early revenue ($5,000–$20,000/month), net burn should not exceed 50% of gross revenue. At growth stage ($50,000+/month), investors expect a clear path to net burn reduction within 18 months. Profitable bootstrapped businesses should have zero net burn. The universal rule that applies at every stage: always maintain 12+ months of runway before making commitments that increase fixed costs.

What is the difference between gross burn and net burn?

Gross burn is total cash spent per month — all expenses combined. Net burn is cash spent minus cash received — expenses minus revenue. Gross burn tells you your cost structure; net burn tells you your survival clock. A business with $20,000 gross burn and $18,000 revenue has a $2,000 net burn and is nearly break-even — 60 months of runway on $120K. The same business with $2,000 revenue has an $18,000 net burn and 6.7 months of runway on $120K — a critical situation despite the identical cost structure. The distinction matters because the fix is completely different: one business needs more revenue, the other needs both.

How much cash should a small business keep in reserve?

Three months of gross burn is the absolute minimum buffer. Six months is the recommended target for most businesses operating in stable markets. For seasonal businesses or those in volatile industries — construction, hospitality, retail — 9–12 months of gross burn in liquid reserves is appropriate. A business with $15,000/month gross burn should keep a minimum of $45,000 in liquid cash: in a business checking or high-yield savings account, accessible within 24 hours, not tied up in equipment, inventory, or accounts receivable.

How do I reduce burn rate quickly?

Three-step rapid reduction: (1) Within 48 hours — audit all recurring subscriptions and cancel anything unused or duplicated. Typical savings: $1,000–$3,000/month. (2) Within two weeks — freeze all non-essential hiring and pause new vendor contracts. (3) Within 30 days — renegotiate your three largest fixed costs: rent (request deferral or reduction), contractor agreements (reduce scope to essential deliverables), and insurance (rebid with a broker). These three steps together typically reduce gross burn by 15–30% without eliminating any revenue-generating activity. Execute in order — the fastest savings come first.

At what runway length should I start fundraising?

Begin at 12 months of runway, not 6 or 3. Fundraising takes significantly longer than founders expect: venture rounds average 3–6 months from first conversation to cash in the bank, SBA loans take 30–90 days, revenue-based financing 2–4 weeks, and angel rounds 4–8 weeks. At 3 months of runway, most fundraising processes cannot close in time, and every investor across every funding source will negotiate aggressively knowing your desperation. At 12 months, you are a creditworthy borrower with time to run a competitive process and walk away from bad terms.

Once you know your runway, the two most actionable next steps are understanding your break-even point — how much revenue makes the net burn rate go to zero — and your profit margin, which tells you how much each additional dollar of revenue contributes to extending the runway. See the break-even analysis guide and the profit margin guide for the specific calculations.