After closing a round: see cash at close (burn until close), extended runway from new capital, and optional post-raise burn. Startup-specific.
Funding and burn assumptions
Current cash, burn until close, timing, new capital, and optional post-close burn.
Understanding the Inputs
Key components for post-funding runway
Cash & Burn
Current cash (today) and monthly burn until close. Cash at close = current cash − (burn × months until close).
Current cash today ($)
Monthly burn until close ($)
Months until funding closes
Funding & Post-Close Burn
New funding at close and optional monthly burn after close (e.g. if you hire). If blank, post-close burn = until-close burn.
New funding at close ($)
Monthly burn after close ($) — optional
Formula Used
Cash at close = Current cash − (Monthly burn until close × Months until close)
Runway after funding = (Cash at close + New funding at close) ÷ Monthly burn after close
Runway today = Current cash ÷ Monthly burn until close. Extension = Runway after funding − Runway today (conceptually; we report extension from new capital).
The Definitive Guide to Post-Funding Runway: Cash at Close and Extended Runway
After you close a round, see how much runway you get: cash at close (burn until close), new capital, and optional post-raise burn. Plan milestones and your next raise with realistic numbers.
Post-funding runway is how many months your startup can operate after the round closes, using cash at close plus the new capital, at your planned post-close burn rate. It answers: "If we close in X months and raise $Y, how long does the money last?"
Why Cash at Close Matters
Cash at close is the cash you have when the round actually closes—not today's balance. If you burn $80K per month and close in 3 months, you have already spent $240K by close. So cash at close = current cash − (monthly burn until close × months until close). If you burn more or close later, you have less cash when the new money lands; this calculator reflects that so you see realistic extended runway instead of an optimistic back-of-envelope number.
Why Model Post-Close Burn Separately?
Many startups increase burn after a round (hiring, marketing, office). If you leave "monthly burn after close" blank, we use the same burn as until close. Enter a higher post-close burn to see how much runway you actually get once you scale spend—often 20–40% less than if burn stayed flat.
The Formulas and Components
The calculator uses a small set of identities. Runway today tells you how long current cash lasts at current burn; cash at close and runway after funding tell you the picture at and after the round.
Cash at Close
Cash at close = Current cash − (Monthly burn until close × Months until close)
Use the same "monthly burn until close" you expect to run at before the round closes. If you plan to cut burn, use the lower number; if you expect a one-off expense, consider it in your current cash or in a separate scenario.
Runway Today and Runway After Funding
Runway today = Current cash ÷ Monthly burn until close
Runway after funding = (Cash at close + New funding at close) ÷ Monthly burn after close
Extension is the additional months you gain from the new capital (and from any change in burn). Zero-cash dates show when cash runs out before and after the round at constant burn.
Interpreting Results and Target Runway
Post-funding runway is expressed in months. A result of 24 months means you can run 24 months at your post-close burn rate before running out of cash (cash at close + new funding).
Target Runway: The 18–24 Month Rule
Many investors and founders target 18–24 months of runway after a round. That gives time to hit milestones (product, revenue, growth) before the next fundraise, and buffers for a 3–6 month raise process. Less than 12 months post-close is tight and increases pressure to raise again quickly or cut burn.
When Extended Runway Is Short
If runway after funding is under 12 months, consider raising more, reducing post-close burn, or extending the time to close (so you have more cash at close). You can also model a higher "months until close" to see how a delayed close reduces cash at close and thus extended runway.
Post-Funding Runway vs. Generic Runway Extension
A generic runway extension calculator often asks for "current cash," "new funding," and "burn." It does not model when the round closes or what happens to cash between now and close.
What This Calculator Adds
This tool is built for a single funding event: you specify months until close and burn until close, so cash at close is explicit. You can also set a different burn after close (e.g. post-hire). That gives a more accurate post-funding runway and extension, and avoids overstating runway by ignoring burn until close or post-raise spend.
Role in Fundraising and Milestone Planning
Use post-funding runway to align the round size and close date with your plan: how long you need to hit the next milestone (e.g. Series A metrics) and when you want to start the next raise.
Scenario Testing
Run scenarios: close in 3 vs. 6 months, same raise size; or same close date with higher post-close burn. You will see how sensitive extended runway is to timing and spend, and can adjust raise size or burn plans accordingly.
Conclusion
Post-funding runway is the number of months your startup can run after the round closes, using cash at close plus new capital at your planned post-close burn. This calculator models a single funding event with explicit cash at close, optional post-raise burn, and extension in months.
Use it to plan runway after a round, stress-test close timing and burn, and pair with a founder dilution calculator to see both runway and ownership impact of the same round.
Frequently Asked Questions
Common questions about post-funding runway
What is post-funding runway?
Post-funding runway is how many months your startup can operate after the round closes, using cash at close plus the new capital, at your planned post-close burn rate. It answers: if we close in X months and raise $Y, how long does the money last at our post-close burn?
Why model burn until close separately?
Cash at close = current cash − (monthly burn × months until close). If you burn more or close later, you have less cash when the new money lands. Modeling burn until close and months to close gives you a realistic cash-at-close number and thus a realistic extended runway instead of assuming you add new funding to today's balance.
Should I increase burn after the round?
Many startups do (hiring, marketing). If you plan to increase burn after close, enter that in "monthly burn after close" so the calculator shows realistic post-funding runway. If you leave it blank, we use the same burn as until close, which can overstate runway if you actually scale spend.
What is a good extended runway target?
18–24 months post-close is common so you have time to hit milestones before the next raise and buffer for a 3–6 month fundraise. Less than 12 months leaves little room for slippage; consider raising more, cutting post-close burn, or accelerating close.
How does this differ from the generic Runway Extension Calculator?
This one is built for a single funding event: it models cash at close (burn until close, months until close), then adds new capital and optional post-raise burn to get post-funding runway and extension. A generic runway tool usually does not model when the round closes or different burn before vs. after close.
What if my close date slips?
Increase "months until close" and recalculate. You will see cash at close drop (more burn before close) and thus less extended runway. That shows why closing on time matters and how much runway you lose for each extra month of delay.
Does the calculator assume constant burn?
Yes. We use one burn until close and one burn after close. Actual burn can vary month to month; use the calculator for planning and run multiple scenarios (e.g. higher burn) to stress-test.
How do I use this with a founder dilution calculator?
Use the same round: same raise size and (if you like) same close timeline. The post-funding runway calculator shows how long the money lasts; the founder dilution calculator shows post-round ownership and dilution. Together they give you runway and equity impact of the round.
Why is cash at close sometimes zero or negative?
If (monthly burn until close × months until close) is greater than or equal to current cash, you run out of cash before the round closes. The calculator caps cash at close at zero. In that case you need to close sooner, cut burn, or secure bridge financing.
What runway should I tell investors I are targeting?
Many founders and boards target 18–24 months of runway after a round. Use this calculator to check that your planned raise size and close date actually get you there at your expected post-close burn, and to explain your assumptions in the plan.
Usage of this Calculator
Practical applications and context
Who Should Use This Calculator?
Founders & CFOsTo plan runway after a round: cash at close and extended runway with optional post-raise burn.
InvestorsTo stress-test runway and burn assumptions before or after a term sheet.
Limitations & Accuracy
Constant burn: Assumes flat burn until close and (optionally) after close; actual burn can vary.
Close timing: Months until close is uncertain; model a range to see sensitivity.
Example
$500K cash, $80K/mo burn, close in 3 months, $2M new funding, same burn after close. Cash at close = $260K. Runway after funding = ($260K + $2M) / $80K ≈ 28 months. Extension from new capital is substantial; if post-close burn rises to $120K/mo, runway drops to about 19 months.
Summary
The Post-Funding Runway Extension Calculator shows runway today, cash at close (before new money), and extended runway after a single funding event.
Enter current cash, burn until close, months to close, new funding at close, and optional post-close burn to see realistic post-funding runway and extension.
Embed This Calculator
Add this calculator to your website or blog using the embed code below:
<div style="max-width: 600px; margin: 0 auto;">
<iframe
src="https://mycalculating.com/category/finance/post-funding-runway-extension-calculator?embed=true"
width="100%"
height="600"
style="border:1px solid #ccc; border-radius:8px;"
loading="lazy"
title="Post Funding Runway Extension Calculator Calculator by MyCalculating.com"
></iframe>
<p style="text-align:center; font-size:12px; margin-top:4px;">
<a href="https://mycalculating.com/category/finance/post-funding-runway-extension-calculator" target="_blank" rel="noopener">
Use full version on <strong>MyCalculating.com</strong>
</a>
</p>
</div>
After closing a round: see cash at close (burn until close), extended runway from new capital, and optional post-raise burn. Startup-specific.
How to use Post-Funding Runway Extension Calculator
Step-by-step guide to using the Post-Funding Runway Extension Calculator:
Enter your values. Input the required values in the calculator form
Calculate. The calculator will automatically compute and display your results
Review results. Review the calculated results and any additional information provided
Frequently asked questions
How do I use the Post-Funding Runway Extension Calculator?
Simply enter your values in the input fields and the calculator will automatically compute the results. The Post-Funding Runway Extension Calculator is designed to be user-friendly and provide instant calculations.
Is the Post-Funding Runway Extension Calculator free to use?
Yes, the Post-Funding Runway Extension Calculator is completely free to use. No registration or payment is required.
Can I use this calculator on mobile devices?
Yes, the Post-Funding Runway Extension Calculator is fully responsive and works perfectly on mobile phones, tablets, and desktop computers.
Are the results from Post-Funding Runway Extension Calculator accurate?
Yes, our calculators use standard formulas and are regularly tested for accuracy. However, results should be used for informational purposes and not as a substitute for professional advice.