SaaS Runway Calculator 2026 Cash / Net Burn = Months

How many months you can keep operating at current cash burn. The single most consequential operational number for venture-backed SaaS between funding rounds. Raise at 9-12 months. Below 6 is dangerous.

Inputs

Gross burn rate
$500K/mo
Total monthly expenses
Net burn rate
$200K/mo
Expenses minus revenue
Runway (net)
15.0 mo
Healthy

12-24 months of runway. Plan next raise and build the metrics narrative.

Worst-case runway (gross burn, zero revenue): 6.0 months

The fundraise window

Series A and Series B fundraises typically take 3-6 months end to end (deck prep, investor meetings, term sheet, due diligence, close). The conventional rule is to start raising when you have 9-12 months of runway remaining. This gives you the 3-6 months for the process plus a 3-6 month operational buffer.

Raising below 6 months of runway is the danger zone. You lose negotiating leverage because investors know you need to close. You risk being forced into a down round (a lower valuation than the prior round) or a bridge loan from existing investors at unfavourable terms. Some companies survive this; many do not.

Threshold guidance

RunwayStatusAction
24+ monthsComfortableFocus on growth and efficiency. No fundraise pressure.
12-24 monthsHealthyPlan next raise. Build metrics narrative.
9-12 monthsRaise window opensBegin fundraise process. Lead with strong metrics.
6-9 monthsActive fundraiseShould be in market. Term sheet ideally in hand.
3-6 monthsDanger zoneLosing leverage. Consider bridge financing options.
Under 3 monthsCriticalCost-cut aggressively. Pursue any viable bridge.

Related

Burn Multiple FormulaBurn Multiple CalculatorGross Margin2026 Benchmarks

Frequently Asked Questions

What is runway?
Runway is the number of months you can keep operating at current cash burn before running out of money. Formula: runway = cash balance / monthly net burn. If you have $3M in the bank and burn $200K per month, your runway is 15 months. Cash-flow positive companies have infinite runway because burn is zero or negative.
What is monthly net burn?
Monthly net burn is your monthly cash expenses minus your monthly cash revenue. It is a cash basis number, not GAAP. If you collected $400K in cash this month and spent $600K, your net burn is $200K. Burn rate excludes non-cash items like depreciation, stock-based compensation, and deferred revenue accruals.
When should you raise more funding?
The conventional rule is raise when you have 9-12 months of runway remaining. This gives you 3-6 months for the fundraise process and still leaves a 6-month operational buffer if the round takes longer than expected. Raising below 6 months is the danger zone; you lose negotiating leverage and may be forced into a down round or bridge loan.
How does runway differ from burn multiple?
Runway is a stock measure (how long can you survive at current burn). Burn multiple is a flow measure (how efficiently are you converting burn into growth). A company can have long runway but a high burn multiple (lots of cash but spending inefficiently) or short runway with a great burn multiple (low cash but growing efficiently). Investors look at both: runway answers will you survive, burn multiple answers should you raise.
What is gross burn vs net burn?
Gross burn is your total monthly cash expenses (salaries, rent, software, marketing) regardless of revenue. Net burn is gross burn minus monthly cash revenue. Net burn is the more useful number for runway because cash revenue offsets cash expenses. A company with $500K gross burn and $300K monthly cash revenue has $200K net burn. Use net burn for runway; track gross burn for cost control.

Updated May 2026