When does your startup actually run out of money?
A single-number runway hides the truth: burn and growth are uncertain, so your cash-out date is a range. This template runs thousands of 24-month scenarios and shows the real spread, and your odds of surviving the year.
Finance Intermediate Monte Carlo Pro engine
After you install, this is the model to open.
When Does the Startup Run Out of Cash?
- In your spreadsheet, click the Sortia icon in the strip of icons down the right-hand edge. No strip? Click the arrow at the bottom-right to open it. You can also use Extensions, then Sortia, then Open Sortia.
- Click Start from a template and put that name in the search box.
- Pick the card with that name and click Load this template. It arrives on a new tab with real numbers already in it.
This one runs on a Pro engine, and every free install includes five full-quality runs on your own numbers, shared across all five Pro engines rather than five for each. After that, Pro is $199/year.
The answer
The naïve runway ($500K ÷ $70K net burn) says ~7 months. The simulation tells a fuller story:
- P5 (unlucky)
- 5 months
- Median
- 8 months
- P95 (lucky)
- 24 months
- Survive 24 mo
- 19%
Half of scenarios run out by month 8, and only about 1 in 5 survive the full 24 months without a change. A single deterministic number would have hidden both the downside (as short as 5 months) and the low odds of making it, exactly the risk you want to see before you commit a plan.
The model
A 24-month cash projection. Revenue grows at an uncertain monthly rate; burn is uncertain too. Runway = the number of months your cash stays positive.
| Starting cash | $500,000 |
| Month-1 revenue | $20,000 |
| Monthly revenue growth | 3% – 12% – 20% (uncertain) |
| Monthly burn | $70K – $90K – $120K (uncertain) |
| Runway (months) | simulated |
Once it is in your sheet
- The model arrives with real numbers in it and runs as it stands, so you can press the button first and understand it second.
- Change the numbers to yours. The sheet marks which cells are inputs and which hold formulas, and most labels carry a note explaining the row.
- Press the run button at the bottom of the panel. It is labeled for the tool you are in, and the result lands on its own tab, with a written reading of it beside the figures.
Never used Google Sheets? Start here goes the whole way, in seven steps, and assumes nothing.
Next question
- What is the business really worth?What Is the Business Worth, as a Range?
- After this round, what do you actually walk away with?What Do the Founders Keep After the Round and the Exit?
- Does the launch still pay after it eats the flagship?Launch With Cannibalization
- What are the odds your product launch actually makes money?Product Launch Go/No-Go NPV
- How big could this product's revenue be by year three?Market Size to Revenue Forecast
- Which projects should we fund this year?Project Portfolio Selector
Every model like this one, and the method behind them: Monte Carlo simulation.