Cash runway.
Calculator for SaaS startups and operators. Enter cash on hand, monthly expenses, monthly revenue. Get months of runway, zero-cash date, and a what-if scenario where you cut expenses some percentage and grow revenue some percentage per month. The chart shows whether the trajectory reaches default-alive (cash flow positive) within 5 years. Mobile-friendly, runs in your browser.
· quick scenarios (overwrites inputs)
· current state
bank balance available right now
gross burn: salaries + tools + infra + rent + everything
net revenue collected per month (MRR for SaaS)
· scenario knobs
How much would you cut expenses and grow revenue if you needed to? The trajectory below shows whether you reach default-alive within 5 years.
percent of monthly expenses you would trim in this scenario
month-over-month percentage growth you can sustain
· your runway
Net-burn runway
9.2 months
months at current pace
Zero-cash date
Mar 6, 2027
when cash hits zero
Gross burn
$150,000
per month, no revenue offset
· scenario trajectory (5-year horizon)
Scenario net burn
$107,500 /mo (initial)
Scenario outcome
13.6 months
· health checks
- warnRunway 9.2 months
Tight. Fundraising at this stage is harder because investors notice the time pressure. Either tighten the burn or raise immediately on whatever metrics you have.
- badBurn/revenue ratio 7.50x
Spending 4x+ revenue. Usually unsustainable unless growth is exceptional. Cut burn or accelerate revenue, ideally both.
- infoScenario adds 4.3 months
The expense cut and revenue growth combination buys you 4.3 extra months but doesn't reach default-alive within 5 years. Either bigger cuts or faster growth needed to flip to profitability.
The four numbers every founder should know in cold-open conversation
- Cash on hand. Bank balance available right now, not including unfunded commitments. If you have a closed-but-not-wired investment, count it only after the wire clears.
- Monthly net burn. Expenses minus revenue. The number that determines how fast you're losing money. Track it monthly and notice when it changes.
- Months of runway. Cash divided by net burn. The single most important survival metric. Under 12 months and investors will notice; under 6 and you need a plan in motion.
- Path to default-alive. A credible plan for revenue growing faster than expenses such that net burn reaches zero before cash does. Not a wishlist; a model with specific assumptions you're willing to defend.
Reading the scenario chart
The chart shows projected cash balance over 60 months given your scenario inputs (expense cut + revenue growth). The dashed line at zero is the runway exhaustion threshold. The orange dot, if it appears, is the month cash hits zero in this scenario. The green dot at the right is the cash balance at month 60.
Three patterns to recognize: (1) line slopes down and crosses zero, meaning cash runs out at the marked month, you need bigger cuts or faster growth; (2) line slopes down but flattens and crosses back up, meaning you reach default-alive at the flat point and accumulate cash thereafter; (3) line slopes up from the start, meaning your current scenario is already cash flow positive and you're accumulating, which usually means the input ARPA / margin / cut assumptions are too optimistic, double-check them.
FAQ
What is cash runway and how is it calculated?
Cash runway is the number of months your bank balance lasts at current burn. Formula: cash on hand ÷ monthly net burn, where net burn is monthly expenses minus monthly revenue. If you have $1.2M in the bank, $150k/month expenses, and $20k/month revenue, your net burn is $130k and your runway is 9.2 months. The calculator does this in real time so you can play with the numbers.
What's the difference between gross burn and net burn?
Gross burn is your total monthly expenses, ignoring revenue. It's the amount you'd burn if revenue went to zero tomorrow (a useful stress-test number). Net burn subtracts revenue: expenses minus revenue. Net burn is the operative runway number if revenue is reliable; gross burn is the floor if you want to model 'what if customers all churn at once'. The calculator shows both.
What does 'default-alive' mean?
Paul Graham's term for a company where revenue grows fast enough that it will reach profitability before cash runs out, given its current growth rate and burn. The scenario explorer in this tool models that: it takes your expense-cut percentage and monthly revenue growth assumption and projects month-by-month cash balance for 5 years. If the trajectory shows revenue exceeding expenses before cash hits zero, you're default-alive in that scenario. The opposite is 'default-dead': cash runs out regardless of growth.
How much runway is safe?
Convention: 18+ months is comfortable, 12-18 is the standard fundraising window (start the process at 12 months to leave 6 for closing), 6-12 is tight (fundraising visibly under time pressure), under 6 is critical. The right answer depends on context: a $2M ARR business with low burn might be fine at 12 months because revenue itself extends runway organically. A pre-revenue company at 12 months should already be raising. The calculator's health check flags these zones.
Should I include my own salary in monthly expenses?
Yes if you're paying yourself out of company funds. The runway calculation is about cash leaving the bank account. If your salary is part of that outflow, include it. If you're a co-founder living on savings and not drawing a salary, leave it out. Some founders run two versions: one with founder comp included (realistic operating burn) and one without (lean-mode survival burn). The lean version is the floor you can stretch to if needed.
Why does this matter for SaaS specifically?
SaaS revenue is recurring and (mostly) predictable, so net-burn runway is meaningfully different from gross-burn runway. A SaaS company at $200k MRR with $300k expenses has $100k net burn; cash runway extends as revenue grows. Compare to project-based businesses where revenue is lumpy and gross burn is the safer number to plan on. The calculator's scenario explorer is specifically calibrated for the SaaS pattern of growing recurring revenue offsetting fixed costs.
What's a good burn-multiple ratio?
Burn multiple = monthly expenses ÷ monthly revenue. Under 1x means expenses are at or below revenue (essentially profitable). 1-2x is typical growth-stage SaaS. 2-4x is the watch zone, investors look for a clear path to compressing it. Over 4x is usually unsustainable unless growth is exceptional (think 20%+ MoM). The calculator's health check flags this against the zones.
Where does my data go?
Nowhere outside your browser. Cash balances, burn rates, revenue numbers, and scenario inputs are kept in your browser's LocalStorage so they're there when you return. No data is sent to Briskly or any third party. The page makes zero network requests when you change inputs.
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