How many months can your company keep going before the bank account hits zero? That number, called runway, tells founders when they must raise money, cut costs, or reach profit. The Runway Calculator estimates it while letting your revenue grow each month.
Enter your cash balance, monthly expenses, starting revenue, and monthly growth rate. You get your estimated runway, a no-revenue runway, and your starting net burn. You also see the month cash runs out and the burn at month six. It suits startups, small businesses, and freelancers planning ahead.
Table of Contents
- What the Calculator Does
- How to Use It, Step by Step
- How the Runway Is Calculated
- Worked Example
- How to Read the Results
- Ways to Extend Your Runway
- Limitations and Assumptions
- FAQs About the Runway Calculator
What the Calculator Does
Four inputs drive a month-by-month projection. Results update as you type.
- Estimated Cash Runway Duration: months until cash reaches zero, or Infinite (Profitable).
- Zero-Revenue Max Runway: cash divided by expenses, as if revenue stopped.
- Initial Net Burn Rate: expenses minus starting revenue.
- Projected Zero-Cash Month: shown as a month number, such as Month 11, or Self-Sustaining.
- Net Burn at Month 6: the projected monthly burn six months out.
- Copy Runway Projection and Reset buttons.
How to Use It, Step by Step
- Enter the money in the bank today in Current Cash Bank Balance ($).
- Enter all monthly spending in Monthly Gross Expenses ($).
- Enter this month's sales in Monthly Initial Revenue ($).
- Enter the expected monthly growth in Monthly Revenue Growth (%). Use 0 for flat revenue.
- Read the runway in the blue box, then check the four cards.
- Press Copy Runway Projection to copy the text, or Reset to restore the sample figures.
How the Runway Is Calculated
The tool plays out your finances one month at a time. Expenses stay flat while revenue grows by your percentage.
Cash-Expenses - Revenue→Repeat Monthly
- Each month: net burn = expenses - current revenue. Cash falls by that amount.
- Then revenue is multiplied by (1 + growth ÷ 100).
- The loop stops when cash is 0 or below, and the month count is your runway.
- If net burn reaches 0 or less while cash remains, it shows Infinite (Profitable).
- Zero-revenue runway = cash ÷ expenses. Initial burn = expenses - starting revenue. It reads "No burn (profitable)" when revenue covers expenses.
Worked Example
Elena runs a small subscription app. She has $250,000 in the bank and spends $38,000 a month. Revenue is $12,000 now and grows 4 percent each month.
| Result | Calculation | Output |
|---|
| Initial Net Burn | $38,000 - $12,000 | $26,000.00 / Mo |
| Zero-Revenue Runway | $250,000 ÷ $38,000 | 6.6 Months |
| Net Burn at Month 6 | $38,000 - $12,000 × 1.04^5 | $23,400.17 / Mo |
| Cash After Month 10 | Month-by-month projection | about $14,073 |
| Estimated Runway | Cash turns negative in month 11 | 11 Months |
| Zero-Cash Month | Month 11 | Month 11 |
Without growth, the same company would last 10 months. Four percent growth buys Elena about one more month.
How to Read the Results
Estimated Cash Runway Duration is always a whole number of months. The final month counts in full, even if cash runs out partway through it. For Elena, $14,073 remains after month 10. Month 11 burns about $20,237, so the true figure is nearer 10.7 months.
Zero-Revenue Max Runway is the worst case. It shows how long cash lasts if sales stopped today.
Initial Net Burn Rate is your starting monthly loss. Net Burn at Month 6 shows how much the loss shrinks if growth holds.
Projected Zero-Cash Month is a month count from today, not a calendar date. Add that many months to the current month to find the date.
Ways to Extend Your Runway
Three moves help: cut expenses, grow revenue faster, or add cash. Start by measuring your costs with the burn rate calculator. Then test whether sales growth is realistic with the revenue growth calculator.
Many founders also check how much of the company they give up when raising money. The startup equity calculator shows that trade. The break-even point calculator shows the sales level where burn reaches zero.
For a personal version, the emergency fund calculator counts the months of bills your savings cover. Compare more options in the finance and business calculator hub.
Limitations and Assumptions
- Expenses are held flat. Planned hires, price changes, and seasonal costs are not modeled.
- Growth is a steady compound rate. Real revenue is often uneven.
- The projection stops at 120 months. A very long runway shows 120+ Months, and the zero-cash card reads Beyond Month 120.
- All four fields need a number, and 0 is fine. Blank, text, or negative entries show a red message, and growth above 100 percent is rejected.
- With 0 cash, the tool shows 0 Months and Already at zero. With 0 expenses, the zero-revenue card reads Not applicable (no expenses).
- Net Burn at Month 6 reads N/A (cash runs out in month N) when cash ends before month six.
FAQs About the Startup Runway Calculator
What is cash runway?
Runway is how many months a company can pay its bills with the cash it has. Revenue that grows can stretch it. Rising costs shorten it.
How much runway should a startup have?
Many advisors suggest 12 to 18 months, since raising money often takes six months or more. Your own number depends on your stage and your market.
Why is my runway longer than cash divided by burn?
The tool lets revenue grow, so the burn shrinks each month. That is why it beats a simple cash-over-burn estimate.
What does Infinite (Profitable) mean?
Revenue has caught up with expenses while you still have cash. After that point the tool assumes you stop losing money.
Can I enter the growth rate as a decimal?
Yes. Enter 2.5 for 2.5 percent a month. Do not type 0.025.
Is the zero-cash month a calendar date?
No. It shows a month number counted from today, such as Month 11.
This calculator gives planning estimates only and is not financial advice. Reviewed for general accuracy by Prof. Dr. Khalil Mudassar, PhD.