SaaS Runway Survival Calculator

How it works

This startup runway calculator does not need a full P&L. Enter cash on hand, monthly recurring revenue (MRR), and monthly burn. Net burn (burn − MRR) is SaaS burn-rate measurement; cash ÷ net burn is months until the bank hits zero — unless you type a month-over-month growth rate. Growth is simulated month by month, so a climbing MRR can catch burn before cash dies. That is the part a one-line spreadsheet cell misses.

1. Cash — the numerator. Operating account only, or include reserves—your call.
2. MRR — money that still arrives if nothing new sells this month. Exclude one-off projects for a conservative view.
3. Burn — payroll, servers, rent, ads: money that leaves even if you sit still.
4. Net burn = burn − MRR. ≤ 0 means you are not on a zero-cash track. Positive means runway = cash / net burn when growth is 0.
5. MoM growth % — optional. 5 means MRR compounds 5% each month and net burn shrinks. Negative is churn. If growth overtakes burn while cash remains, the grade flips to profitable.
6. Reverse target — pick 6 / 12 / 18 / 24 months. The page reverse-solves the starting MRR you need at today’s burn, and the max burn you can afford at today’s MRR.
7. Hire field — add one extra monthly cost (a role, an office) and see how many months you lose.
8. Grades: 18+ months safe, 12–18 watch, 6–12 warning, 3–6 critical, under 3 crisis.
9. Monthly CSV copies the cash / MRR / net-burn path for a board deck. KRW and USD toggles change presets and formatting only — numbers are not FX-converted.

Indie, seed, and profitable presets help you feel the numbers. Copy the runway summary into Slack or an investor update. Everything stays in the browser. Real drain depends on tax dates and collection lag—treat this as a first-pass warning, not accounting.

FAQ

Why not a spreadsheet?

Spreadsheets do not spit out “7 months 12 days,” a calendar date, a grade card, a 12-month reverse MRR, and a copy-ready sentence in one tap. Compounding MRR also needs a loop, not cash/(burn-mrr).

What about variable costs?

Put recurring ads and payment fees into burn for a conservative runway. Or subtract COGS-like costs from MRR.

Is the zero-cash date a real calendar day?

Yes—from today, using 30.4375 days per month. Payroll spikes and VAT deadlines are not modeled.

Does growth always extend runway?

Only if you actually grow. A 0% field is the stalled-revenue case founders should quote first. High growth can “catch up” and never hit zero; that path is labeled separately so you do not confuse it with already-profitable net burn.