Free cash burn rate calculator for US startups and small businesses. Compute gross burn, net burn, simple runway, growth-adjusted runway, and the funding gap needed to reach your target runway.
1. Cash & Burn Rate
Total cash available today.
Total monthly cash out — this is the gross burn.
Monthly cash in from operations.
Cash you expect to raise in the future.
2. Growth & Projections
Compounded month over month.
Compounded month over month.
Month the additional funding is received. 0 = no funding.
Target runway used to compute the funding gap.
3. Reference & Notes
CASH BURN RATE ANALYSIS
Runway & Financial Projection
Reference: CBR-2026-001
Date:
Current Cash$500,000.00
Net Burn Rate$40,000.00
Gross Burn Rate$50,000.00
Simple Runway12.5 Months
Adjusted Runway (with growth)13.3 Months
Months to 6-Mo Buffer7.3 Months
Funding Gap to Target$220,000.00
Runway Status🟢 Healthy
Monthly Cash Flow Breakdown
Revenue$10,000.00
Expenses−$50,000.00
Net Cash Flow−$40,000.00
Cash Remaining$500,000.00
Cash Projection (Adjusted for Growth)
Month 3$396,800
Month 6$295,900
Month 9$196,400
Month 12$98,100
Runway EndMonth 14
Cash Burn Rate Formula
Net Burn = Monthly Expenses − Monthly Revenue · Simple Runway = Cash ÷ Net Burn
Your net burn rate is $40,000.00/month. Simple runway is 12.5 months; the growth-adjusted runway is 13.3 months.
Notes
Cash burn rate analysis for startup planning
This calculation is for informational and educational purposes. Actual runway depends on execution, market conditions, and future cash needs. Consult a CPA or financial professional for business planning decisions.
Prepared By
Date
GUIDE
How to Use This Cash Burn Rate Calculator
This free cash burn rate calculator helps startup founders and small
business owners measure how fast cash is leaving the business and how many months of
runway remain. Enter your cash, monthly burn, revenue, and growth assumptions and the
calculator shows gross burn, net burn,
simple runway, growth-adjusted runway, and the
funding gap needed to reach your target runway. Pair it with our
business ROI calculator
to weigh growth investments against runway, or use the
break-even calculator
to find the revenue level at which net burn reaches zero.
1
Enter Cash & Burn
Enter current cash, monthly operating expenses (gross burn), monthly revenue, and any additional funding you expect.
2
Set Growth Assumptions
Enter monthly revenue growth, monthly expense growth, and the month you expect additional funding to arrive.
3
Set a Runway Target
Enter your target runway in months — the calculator uses it to compute the funding gap you need to close.
4
Review Both Runway Metrics
Compare simple runway (cash ÷ net burn) with growth-adjusted runway to see whether growth extends or shortens your runway.
5
Save, Print or Export
Save a draft in your browser, print results, or download a PDF for your records.
STARTUP EDUCATION
What Does a Cash Burn Rate Calculator Calculate?
A cash burn rate calculator — sometimes called a
runway calculator or startup burn calculator — measures
how quickly a business is consuming its cash reserves and how many months of operating
runway remain. It separates the gross burn (total monthly spending) from the net burn
(spending minus revenue), which is the number that actually determines runway.
Key cash burn rate calculations
Gross Burn Rate: Total monthly operating expenses.
Net Burn Rate: Gross burn minus monthly revenue — the actual monthly cash loss.
Simple Runway: Current cash ÷ net burn. How many months of cash remain at current burn.
Adjusted Runway: Runway projected forward with monthly revenue and expense growth compounding.
Funding Gap: The additional cash needed to reach your target runway, after accounting for current cash and expected funding.
Months to 6-Month Buffer: How long until you hit the runway level where fundraising typically starts.
Who can use this cash burn rate calculator?
Startup Founders: Track runway and time fundraising rounds accurately.
Small Business Owners: Monitor cash consumption during seasonal slumps or expansion.
CFOs and Finance Teams: Model best-case and worst-case runway scenarios.
VCs and Angel Investors: Evaluate portfolio company runway and funding needs.
Accountants and Advisors: Provide defensible runway estimates for clients.
METHODOLOGY
Cash Burn Rate Calculator Methodology
MoneyTool uses standard startup-finance formulas for burn rate and runway. The
calculator is designed to be transparent about what each metric does and does not
capture.
1. Gross and net burn
Gross burn = Monthly operating expenses
Net burn = Monthly operating expenses − Monthly revenue
Net burn is the number used for runway because it reflects the actual monthly cash
loss. When net burn is negative, the business is generating cash and runway is
effectively unlimited.
2. Simple runway
Simple runway (months) = Current cash ÷ Net burn
This is the classic runway formula used by founders and VCs. It assumes constant burn and no additional funding.
3. Growth-adjusted runway
The calculator projects each month forward, applying the revenue growth rate to
revenue and the expense growth rate to expenses (compounded monthly), and adds any
expected funding at the specified month. Runway ends the first month cash drops to
or below zero. This shows whether growth accelerates or shortens runway.
Revenuem = Revenuem−1 × (1 + revenue growth%)
Expensesm = Expensesm−1 × (1 + expense growth%)
Cashm = Cashm−1 + Revenuem − Expensesm + Fundingm
4. Funding gap
Required cash = Net burn × Target runway
Available cash = Current cash + Expected future funding
Funding gap = max(0, Required cash − Available cash)
This is the additional capital you need to raise (beyond what you already have and
what you expect to raise) to reach your target runway at the current net burn rate.
5. Months to 6-month buffer
Founders are typically advised to begin fundraising with at least 6 months of runway
remaining, because a round usually takes 3–6 months to close. The calculator reports
how many months until you hit that threshold under your growth-adjusted projection.
Important assumptions
Revenue and expenses are compounded monthly at the rates you enter.
Additional funding is added once, at the month you specify.
Growth rates are constant and flat throughout the projection.
Taxes, debt service, and financing costs are not modeled.
This is an educational planning estimate, not a financial projection or cash forecast.
Not a substitute for professional financial, tax, or investment advice.
MoneyTool separates calculation results from financial education and personalized
planning. The calculator uses documented startup-finance formulas, while external
business guidance should be verified with authoritative sources.
Author and editorial responsibility
Methodology reviewed by the
MoneyTool Finance Expert Team,
a group of accountants, CPAs, and personal-finance analysts who maintain
MoneyTool's calculator library and financial education content.
Last reviewed:
| Startup burn rate and runway math
Next review: When calculation logic, supported inputs, or relevant guidance changes.
Authoritative U.S. business and startup finance resources
U.S. Small Business Administration (SBA) — Plan Your Business:SBA Plan Your Business
covers business planning, financial projections, and cash management.
U.S. Small Business Administration (SBA) — Financing:SBA Funding Programs
covers SBA-backed financing for working capital and growth.
U.S. Securities and Exchange Commission (SEC) — Investor.gov:SEC Investor.gov
provides investor education on risk, cash, and business performance.
Financial Industry Regulatory Authority (FINRA):FINRA Investor Education
offers practical guidance on evaluating investments and returns.
Internal Revenue Service (IRS) — Small Business Tax Center:IRS Small Business Tax Center
covers tax treatment of business expenses that drive burn rate.
Consumer Financial Protection Bureau (CFPB):CFPB Consumer Tools
provides financial education for individuals and small business owners.
Federal Trade Commission (FTC) — Business Guidance:FTC Business Guidance
covers advertising, disclosure, and fair-lending rules for business financing.
U.S. Bureau of Labor Statistics (BLS) — Consumer Price Index:BLS CPI
is the official source for inflation data that affects real burn rate and runway.
External resources are provided for education and verification. MoneyTool is not affiliated
with or endorsed by the SBA, SEC, FINRA, IRS, CFPB, FTC, or BLS.
BEST PRACTICES
Tips for Cash Burn Rate Management
Runway is the single most important metric for early-stage businesses. Manage it
actively — not passively — by tracking burn monthly and planning fundraising well
in advance.
📊
Track Burn Monthly
Recalculate burn and runway every month. Small drifts become big surprises if left unchecked for a quarter.
📈
Plan 12–18 Months Ahead
Maintain at least 12–18 months of runway for stability, or 6–9 months before you begin fundraising.
💰
Reduce Burn Deliberately
Identify 3–5 cost categories that can shrink without hurting growth, then cut them before you need to.
🎯
Fundraise with 6–9 Months Left
Rounds take 3–6 months to close. Starting with less than 6 months of runway weakens your negotiating position.
🔄
Grow Revenue Over Expense
Growth that outpaces expense growth extends runway. Growth that lags shortens it — even if revenue is up.
✅
Consult a Professional
For financing decisions, engage a CPA or financial advisor to validate projections and structure.
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Cash burn rate is the rate at which a company spends its cash reserves. Gross burn is total monthly operating expenses; net burn is gross burn minus monthly revenue.
How is cash runway calculated?
Simple runway is current cash balance divided by monthly net burn rate. Adjusted runway accounts for expected revenue growth and expense growth over time.
What is a healthy cash runway?
A healthy runway is typically 12–18 months. Startups are often advised to begin fundraising when they have 6–9 months of runway remaining to allow for a 3–6 month fundraising process.
What is the difference between gross burn and net burn?
Gross burn is total monthly operating expenses. Net burn is gross burn minus monthly revenue — it is the actual cash loss per month and is the correct denominator for runway calculation.
What is a funding gap?
A funding gap is the additional cash you need to reach a target runway after accounting for current cash and expected future funding. It tells you how much capital to raise.
Is this cash burn rate calculator free?
Yes. MoneyTool provides this cash burn rate calculator free for educational and planning use.
Can I save my cash burn rate analysis?
Yes. Save Draft stores the calculator inputs in your browser. Print Results and Download PDF can be used to keep a copy of the displayed analysis.
LEGAL
Cash Burn Rate Calculator Disclaimer
This cash burn rate calculator provides estimates for informational and educational
purposes. It does not constitute financial, legal, tax, accounting, or investment
advice. Actual runway depends on execution, market conditions, future cash needs,
and financing outcomes that cannot be fully modeled here.
Estimates only: Results depend on the inputs and assumptions described in the methodology.
Not a cash forecast: The calculator projects constant growth rates and does not model seasonality, lumpy revenue, or contingency costs.
No financing advice: The funding gap is an estimate; the amount you raise depends on dilution, valuation, and investor demand.
Verify before decisions: Review your cash position with a CPA or financial advisor before making financing or spending decisions.
Last methodology review: .
Calculator logic and educational content should be reviewed again whenever the methodology,
supported inputs, or relevant external guidance changes.
