Free founder tool
Startup runway and raise size calculator
Estimate when cash runs out and how much additional cash covers your target plus a buffer. Adjust revenue and expense growth as you type. Free, with no login.
| Measure | Result |
|---|---|
| Cash first goes below zero | Month 6 |
| Additional cash needed for target plus buffer | $200,000.00 |
| Month | Ending cash |
|---|---|
| Starting cash | $100,000.00 |
| 1 | $80,000.00 |
| 2 | $60,000.00 |
| 3 | $40,000.00 |
| 4 | $20,000.00 |
| 5 | $0.00 |
| 6 | -$20,000.00 |
These figures come from the numbers you enter. Vanward does not check or validate them, and this is not a valuation, a 409A, or legal or tax advice. Your company's cap table and signed documents are the record.
How the math works
Cash runway depends on cash received and cash spent. Each month, this calculator adds revenue to cash and subtracts expenses. Month 1 uses your entered amounts. From month 2, revenue and expenses grow at their respective monthly rates. The result names the first month ending below zero, up to a 60-month projection.
For example, $100,000 in cash, $10,000 in monthly revenue and $30,000 in monthly expenses means $20,000 of monthly net burn. Cash reaches zero at the end of month 5 and goes below zero in month 6. With no growth, a 12-month target plus a 3-month buffer needs $300,000 in total cash. After the $100,000 already available, the additional cash needed is $200,000.
When growth changes burn over time, a single cash-divided-by-burn figure is not enough. The raise estimate covers the deepest cash shortfall across the target and buffer, even if revenue later catches up. It assumes the extra cash is available at the start and excludes fundraising costs unless you include them in expenses.
Questions founders ask
- How is startup runway calculated?
- For flat revenue and expenses, divide cash by monthly net burn to find the months cash covers. This calculator projects each month and reports the first month ending below zero. It also supports monthly growth in revenue and expenses.
- Does a zero cash balance count as running out?
- The projection stops when cash goes below zero. A month ending at exactly zero stays in the series. For example, cash covering five full months at flat burn goes below zero in month six.
- How does the calculator estimate a raise size?
- It projects cash across the target months plus buffer months, then finds the largest cash shortfall. The additional cash needed covers that shortfall after using your existing cash. It rounds the required amount up to the nearest cent.
- What if revenue covers expenses?
- If cash never goes below zero within 60 months, the result says it lasts beyond the projection. That is not a promise of unlimited runway. Expense growth can still overtake revenue, and collection timing can change the outcome.
- What should I include in cash revenue and expenses?
- Use money received and paid, including payroll, vendor payments, debt payments and taxes where applicable. Exclude noncash accounting charges. The model assumes monthly cash flows and fixed growth rates, so review it when hiring plans, collections or costs change.
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