Startup Runway Calculator: Months of Cash at Current Burn
Work out a startup's runway — the number of months its current cash will last at the current rate of net burn.
Adjust the inputs and select Calculate for a full breakdown.
Compare Common Scenarios
How the numbers shift across typical situations for this calculator:
| Scenario | Months of runway |
|---|---|
| $500k cash · $50k burn | 10 |
| $2M cash · $150k burn | 13.33 |
| $120k cash · $20k burn | 6 |
| $8M cash · $400k burn | 20 |
How This Calculator Works
Enter the cash on hand and the net monthly burn — cash out minus cash in. The calculator divides one by the other to give the months of runway. The figure assumes today's burn rate holds; revenue growth extends it, faster hiring shortens it.
The Formula
Recovery Period
Fixed Cost is the upfront amount, Benefit per Period is the recurring gain that pays it back
Worked Example
A startup with $500,000 in the bank burning $50,000 a month has 10 months of runway. Under 12 months is usually the trigger for opening the next round — fundraising itself takes months, and closing on empty rarely ends well.
Key Insight
Runway is the most important number on a startup's dashboard, because it sets the deadline for every other decision. Most founders watch a six-month minimum: any closer and the choice between cutting costs and raising is no longer theirs to make.
Runway math and fundraising triggers
FORMULA. Cash / Monthly Net Burn = Months Runway.
Example. $5M cash. $250K/month burn. Runway = 20 months.
INDUSTRY RULES OF THUMB.
Substantial — 18-24 months runway target normal markets.
Substantial — 24-36 months target tough markets (2022-2024).
Substantial — start fundraising 6-9 months before zero.
Substantial — "default alive" (Graham): can survive without raising more.
BURN TYPES.
GROSS BURN. Total cash out monthly.
NET BURN. Gross burn − revenue. Substantial — actual cash consumption.
GROWTH-STAGE substantial — substantial gross burn high but net burn declining.
MILESTONES.
Substantial — milestone-based fundraising tranches common.
Substantial — hit ARR milestone unlocks next tranche.
PRO-RATA reserves from existing investors substantial.
FUNDRAISING TIMING.
Substantial signal substantial — 12-18 months runway start raising.
Substantial — 6 months runway substantial crisis mode.
Substantial — investors avoid "forced raises" — substantial down-round risk.
Substantial Q1-Q2 substantial active VC quarters.
Substantial August / December slowdown.
BRIDGE ROUNDS substantial.
Substantial 2022-2024 — substantial bridge rounds.
Substantial SAFE / convertible.
Substantial existing investor leads.
Extending runway — cost cuts, revenue acceleration, financing alternatives
COST CUTS.
Substantial 2022-2024 substantial layoffs (Meta, Google, Twitter, Stripe, etc.).
Layoffs substantial — substantial fastest runway extension.
Substantial 10-30% workforce reduction substantial extends runway 3-9 months.
Substantial — discretionary spend cut.
Substantial — vendor renegotiation.
Substantial — real estate sublease.
REVENUE ACCELERATION.
Substantial — push existing customers upsell.
Substantial — annual prepay discounts.
Substantial — new pricing.
Substantial — narrow ICP (Ideal Customer Profile).
FINANCING ALTERNATIVES.
VENTURE DEBT. Substantial. SVB (now First Citizens), Hercules, TriplePoint substantial.
Substantial — 12-24 month interest-only periods.
Substantial — covenant requirements.
Substantial — extends runway 6-12 months equity-free.
REVENUE-BASED FINANCING.
Substantial. Pipe, Capchase, Lighter Capital.
Substantial advance against ARR.
Substantial — no equity dilution.
FACTORING / RECEIVABLES.
Substantial for B2B with substantial AR.
Substantial — Net 60-90 terms substantial.
BRIDGE financing.
Substantial existing investor commit additional capital.
Substantial — SAFE / convertible terms.
Substantial — anti-dilution protections.
STRATEGIC PARTNERSHIPS.
Substantial — corporate equity / partnership.
Substantial — substantial signaling effect.
EXIT / ACQUISITION substantial.
Substantial — substantial acquihire vs acquisition.
Substantial 2022-2024 substantial acquihires.
OPERATIONAL.
Substantial automate substantial.
Substantial outsource non-core.
Substantial slow hiring substantial.
DEFAULT-ALIVE substantial Paul Graham concept.
Substantial — substantial can become profitable before runway out without raising.
Substantial — substantial 2022-2024 mantra.
Substantial difficult execution but substantial reduces fundraising stress.
Startup runway benchmarks + actions (2024)
Reference runway thresholds + actions.
| Runway | Status | Action |
|---|---|---|
| 36+ months | Substantial cushion | Optimize growth |
| 24-36 months | Healthy | Plan next raise |
| 18-24 months | Normal | Start fundraising process |
| 12-18 months | Tight | Active fundraising |
| 6-12 months | Urgent | Cost cuts + accelerated raise |
| 3-6 months | Crisis | Layoffs + bridge / acquisition talks |
| <3 months | Existential | Acquihire / shutdown |
| Venture debt extension | +6-12 months | — |
| Default-alive (profitable) | Infinite | — |
18-24 months target normal markets; 24-36 months target tough markets (2022-2024). Venture debt (SVB now First Citizens, Hercules) substantial 6-12 month extension equity-free. Revenue-based financing (Pipe, Capchase) substantial AR-based. Layoffs substantial fastest extension (10-30% headcount = 3-9 months). YC + First Round + Carta data.
Frequently Asked Questions
What is runway?
It is the number of months a startup can keep operating at its current burn rate before cash runs out. Cash on hand divided by net monthly burn.
Gross or net burn?
Use net — cash out minus cash in. Gross burn ignores revenue and overstates how quickly the bank account drains, which paints an unfair picture of a revenue-generating company.
When should I start fundraising?
Most founders kick off a round with 9 to 12 months of runway left. Fundraising itself takes months, and conditions almost always tighten as the deadline approaches.
What if burn is uneven?
Use the recent three- to six-month average. A single noisy month — a one-off bonus, a large refund — distorts the figure and is not what 'current burn' usually means.
Does this assume revenue stays flat?
Yes. The runway shown is at today's net burn. Revenue growth lengthens it, faster hiring shortens it — rerun the figure whenever burn changes meaningfully.
When is this calculator unreliable?
Less reliable when burn lumpy (large quarterly tax/insurance payments), when growth investments planned mid-period (substantial hiring/marketing spike), when revenue ramping (use trailing 3-month avg net burn), when one-time receipts/payments distort, when accounts receivable timing affects cash availability, when accounts payable extensions affect cash but not P&L, or when milestone-based funding (tranches) treated as committed. 18-24 months target normal markets; 24-36 months tough markets.
References & Authoritative Sources
- Y Combinator — Startup School + Standard Practices · consulted June 1, 2026 · Accelerator best practices
- First Round Capital — State of Startups Report · consulted June 1, 2026 · VC research
- Carta — State of Private Markets · consulted June 1, 2026 · Equity management + analytics
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Methodology & Review
Runway (months) = current cash / monthly net burn. Net burn = cash out − cash in. Industry rule of thumb 2024: maintain 18-24 months runway. Below 12 months substantial fundraising pressure. Below 6 months substantial crisis. Calculator returns runway in months + fundraising decision date. RELIABILITY: Reliable for documented cash position + burn. Less reliable when (a) burn lumpy (large quarterly expenses); (b) growth investments planned mid-period; (c) revenue ramping (use trailing 3-month avg); (d) one-time receipts/payments; (e) accounts receivable timing; (f) accounts payable extensions affect cash but not P&L; (g) milestone-based funding (tranches).
Reviewed according to the CalcDomain Editorial Policy & Calculator Methodology. We document formulas, edge cases, sources, update dates, and correction paths for calculator pages.
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