What Runway Zero Calculates
The exact month cash hits zero at today's burn and revenue.
Runway Zero answers one question: at current pace, how many months until the bank account is empty?
Runway is the months before cash runs out. Runway Zero takes three numbers — cash on hand, monthly burn, monthly revenue — and projects the exact month the balance crosses zero. Crisis mode forces revenue to zero and exposes the worst-case floor. Your current reading:
Runway = Cash ÷ (Burn − Revenue) Crisis Mode: Runway = Cash ÷ Burn // revenue forced to 0 Zero Date = today + Runway months
- Sum every outflow that clears the bank each month; label total Burn.
- Net revenue only — subtract refunds, chargebacks, processor fees before entering.
- Divide Cash by (Burn − Revenue). Negative denominator means indefinite; stop.
- Run Crisis mode: force revenue to zero; accept that number as the real floor.
- If runway < 6 months, cut burn tonight. If < 3, triage bills before anything else.
Quick answer
Runway Zero answers one question: at current pace, how many months until the bank account is empty?
▸ Key Specs
- ▸ Formula: Runway = Cash ÷ (Burn − Revenue). Revenue ≥ burn → runway is indefinite.
- ▸ Burn is every outflow: salaries, rent, infrastructure, contractors, taxes. If it leaves the bank monthly, include it.
- ▸ Crisis mode forces revenue to $0. Use it for customer-concentration and market-shock scenarios. Current projection:
runway not calculated . - ▸ Inputs persist in localStorage on this device. Nothing leaves the browser.
- ▸ Zero Date is the month projection crosses below zero — the bankruptcy date at current trajectory.
▸ Worked Examples
- $250k cash, $65k burn, $22k revenueNet burn $43k/month. Runway ≈ 5.8 months (
runway not calculated live). Zero date lands roughly 6 months out. - Same numbers, Crisis mode onRevenue drops to $0. Runway collapses to ~3.8 months ($250k ÷ $65k).
- $100k cash, $10k burn, $15k revenueNet positive $5k/month. No Zero Date — runway is indefinite at this pace.
When to use which tool
- CYAN · STABLE — Runway over 18 months — raise from strength, hire patiently.
- GOLD · GUARDED — Runway 6-18 months — fundraise window open; cut burn or accelerate revenue.
- MAGENTA · CRITICAL — Runway under 6 months — already late; cut deep or accept any terms available.
Related
- Runway ZeroCalculate the exact month your cash runs out. Crisis toggle models a worst-case scenario with revenue zeroed.
- When to Check Your Cash RunwaySix specific moments when recalculating runway changes your next move.
- Six Runway Calculation MistakesThe common errors that make runway look longer than it actually is.
Frequently asked questions
› Is runway the same as break-even? Trust & accuracy
No. Runway is "how long until cash runs out at current burn". Break-even is "at what volume do revenues cover fixed costs". A business can have long runway and no break-even path — or short runway with a clear break-even coming.
› Should I subtract taxes from revenue? Trust & accuracy
Use net revenue (after refunds, chargebacks, payment processor fees). Put quarterly tax payments on the burn side in the month they hit.
› What counts as "indefinite"?
Revenue ≥ burn for the current month. The calculator marks it Indefinite — but real businesses should still stress-test with Crisis mode, since indefinite assumes today's revenue holds forever.
› How should I use a decision framework in real life? How-to
Use a decision framework to expose the tradeoff, not to outsource the decision. Write down the inputs, compare the output with your constraints, then ask what would change the answer. The strongest use is scenario testing: base case, conservative case, and failure case.
› Is this financial, legal, or tax advice? Trust & accuracy
No, this is not legal, financial, tax, medical, or professional advice unless the page explicitly says that use case is supported. It organizes assumptions so you can inspect them. Verify high-stakes choices with qualified people who can review facts, contracts, regulations, and downside risk.