Free ForeverNo SignupFundraise Timing IncludedUpdated 2026

Startup Runway Calculator

Know exactly how many months of cash you have โ€” and when to start your next fundraise.

Runway is the number of months your startup can operate before running out of cash. It's calculated by dividing cash on hand by monthly net burn rate. The rule: start your next fundraising process when you have 12โ€“18 months of runway remaining โ€” enough time to close a round without negotiating from desperation.

Current bank balance available for operations (exclude restricted cash)

$

Total expenses minus monthly revenue โ€” actual cash drain per month

$

Expected monthly increase/decrease in burn (+ for increase, โˆ’ for reduction)

$

The Formula

Runway (months) = Cash on Hand รท Monthly Net Burn Rate

In plain English

Divide your cash on hand by your monthly net burn rate. The result is the number of months before you run out of cash.

Worked Example

Cash: $2,000,000. Net burn: $90,000/month. Runway = $2,000,000 รท $90,000 = 22 months. Start fundraising in ~7 months.

How to Extend Your Runway Without Raising

Runway extension doesn't always require raising more capital. Cost cuts can be highly effective: reducing burn by 20% extends runway by 25%. The three highest-impact levers: headcount (defer open roles, freeze discretionary hiring), reduce low-ROI marketing spend, and renegotiate vendor contracts.

On the revenue side: improve collections (annual prepay discounts can front-load cash), accelerate deals in the pipeline, and reduce churn to protect existing revenue. Revenue improvements are more valuable than equivalent cost cuts because they also improve burn multiple.

The Default Alive Test

Paul Graham's "Default Alive" question: if your expenses and revenue follow their current trajectories, will you reach profitability before running out of cash โ€” without raising more money? Knowing the answer to this question fundamentally changes your fundraising posture. Default Alive founders raise from strength; Default Dead founders raise from fear.

When to Time Your Fundraise

Ideal fundraising timing: 15โ€“18 months of runway remaining, recent strong metrics (2โ€“3 months of MoM acceleration), and a clear narrative for why now is the right time to invest.

Fundraising timeline reality: first meeting to term sheet takes 6โ€“12 weeks for angels and seed; 2โ€“4 months for Series A; 4โ€“6 months for Series B+. Always add 4 weeks for legal and closing. Plan accordingly.

18 mo

Ideal runway to start fundraising

4โ€“6 mo

Time to close a Series A

12 mo

Minimum runway before starting to raise

20%

Burn cut โ†’ 25% runway extension

Runway Benchmarks for Startup Decision-Making (2026)

RunwayStatusRecommended ActionFundraisingStatus

24+ months

ExcellentScale with convictionOptional / strategic

18โ€“24 months

HealthyPrepare fundraiseBegin in 3โ€“6 months

12โ€“18 months

CautionStart fundraise nowActive outreach

6โ€“12 months

UrgentRaise and cut burnEmergency process

< 6 months

CriticalCut + bridge + M&AAll options on table

Source: Y Combinator Startup Advice ยท Sequoia Capital RIP Good Times Framework (updated 2024)

Common Mistakes

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Calculating runway from gross burn instead of net burn

Gross burn (total spend) overstates the cash drain if you have meaningful revenue. Runway should use net burn (expenses minus revenue). Using gross burn makes runway look shorter than it is โ€” useful for conservative planning, but misleading for investor conversations.

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Not modelling burn increase as you scale

A common mistake: calculating runway at current burn while planning to hire 10 people next quarter. Model runway using projected burn, not today's burn. Account for hiring plans, marketing investments, and infrastructure costs in your 12-month model.

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Waiting too long to start fundraising

The single most expensive mistake. Starting a fundraise with 6 months of runway forces you to accept unfavourable terms โ€” investors know you're desperate. Start at 15โ€“18 months runway, even if you don't feel the urgency. The process always takes longer than expected.

Frequently Asked Questions

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