Free tool
Zero cash date and startup runway calculator
Enter your cash, revenue, and expenses to get your runway and your zero-cash date. Then model what a new hire (at fully loaded cost) or an annual contract payment does to both.
Net monthly burn
-$25,000
Runway
10.0 months
Zero-cash date
August 31, 2027
| Month | Inflows | Outflows | Closing balance |
|---|---|---|---|
| Dec 2026 | $30,000 | $55,000 | $225,000 |
| Dec 2026 | $30,000 | $55,000 | $200,000 |
| Jan 2027 | $30,000 | $55,000 | $175,000 |
| Mar 2027 | $30,000 | $55,000 | $150,000 |
| Mar 2027 | $30,000 | $55,000 | $125,000 |
| May 2027 | $30,000 | $55,000 | $100,000 |
| May 2027 | $30,000 | $55,000 | $75,000 |
| Jul 2027 | $30,000 | $55,000 | $50,000 |
| Jul 2027 | $30,000 | $55,000 | $25,000 |
| Aug 2027 | $30,000 | $55,000 | $0 |
| Oct 2027 | $30,000 | $55,000 | -$25,000 |
| Oct 2027 | $30,000 | $55,000 | -$50,000 |
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How this calculator works
The math, in plain terms:
- Runway is cash divided by net monthly burn (expenses minus the cash you collect, not booked revenue).
- The zero-cash date projects your balance month by month and interpolates the day your balance crosses zero.
- New hires are costed at 1.3x base salary, the common planning multiplier for payroll taxes, benefits, and equipment.
- An annual contract is one inflow on one date. That single payment can move your zero-cash date by months without changing your average burn at all.
If your revenue and expenses are smooth, this estimate is close. If your cash arrives in lumps (annual contracts, seasonal spikes, late-paying clients), a monthly average misleads: Paul Graham's default alive or default dead question deserves a date-level answer. Our guides explain runway vs burn rate, how to calculate your zero cash date week by week, and our default alive checklist for founders. For the weekly discipline, see our guides to cash flow forecasting and the 13-week cash flow forecast, start from the free 13-week cash flow template, or check whether you will make payroll, learn the 7-day response in what happens if you miss payroll, or map your pay dates with the payroll calendar calculator.
Zensus answers the same questions with your live financials: it connects your bank, QuickBooks, and HubSpot and keeps your zero-cash date current as real transactions clear. Zensus Pro is $199 per month.
Frequently asked questions
- How do I calculate startup runway?
- Divide your current cash balance by your monthly net burn: expenses minus the cash customers actually pay you, not booked revenue. $250,000 in cash with $25,000 of net monthly burn is 10 months of runway. This calculator also projects the calendar date your balance crosses zero, which is the number investors actually ask about.
- What is a zero-cash date?
- Your zero-cash date is the calendar date your bank balance hits zero if nothing changes. It is more useful than a month count because it forces payment timing into the math: an annual contract landing in March changes the date, even though it does not change your average burn.
- What does a new hire really cost?
- Plan on 1.25x to 1.4x base salary once payroll taxes, benefits, and equipment are included. This calculator uses 1.3x, so a $120,000 hire costs about $13,000 a month of runway, not $10,000.
- How much runway should a startup have?
- There is no universal number. 18 to 24 months after a raise is a common rule of thumb, but the right amount depends on your stage and the next milestone you need to reach. Carta data shows the median time from seed to Series A ran over two years for startups that raised in late 2024, so a 12-month plan leaves little room for a slow fundraise.
- Is this calculator accurate for lumpy revenue?
- A flat monthly average hides timing: an annual contract is one big inflow on one date, not twelve smooth slices. Use the annual contract toggle here for a rough view, then a date-aware cash flow forecast like Zensus when the answer has to be right to the week.
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