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Startup runway calculator (AED, SAR or USD)
Runway is how many months your cash lasts at your current pace: runway = cash in the bank ÷ net monthly burn, where net burn is the cash that goes out each month minus the cash that comes in. Enter your numbers below to see your runway, the month your cash runs out and a month-by-month chart.
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Your runway
12 months
At this pace, cash runs out in about 12 months.
- Net burn this month
- AED 75,000
- Gross burn this month
- AED 135,000
Month-by-month table
| Month | Net burn | Month-end cash |
|---|---|---|
| 1 | AED 75,000 | AED 825,000 |
| 2 | AED 75,000 | AED 750,000 |
| 3 | AED 75,000 | AED 675,000 |
| 4 | AED 75,000 | AED 600,000 |
| 5 | AED 75,000 | AED 525,000 |
| 6 | AED 75,000 | AED 450,000 |
| 7 | AED 75,000 | AED 375,000 |
| 8 | AED 75,000 | AED 300,000 |
| 9 | AED 75,000 | AED 225,000 |
| 10 | AED 75,000 | AED 150,000 |
| 11 | AED 75,000 | AED 75,000 |
| 12 | AED 75,000 | AED 0 |
How do you calculate startup runway?
Runway is a cash measure, not a profit measure. Use the money that actually lands in and leaves your bank accounts, averaged over the last three months so one unusual month doesn't skew it.
- 1
Add up the cash you can spend
Total the balances of every business bank account today. Leave out money you've raised but not yet received.
- 2
Work out your monthly cash out (gross burn)
Average the last three months of payments: salaries, rent, software, suppliers, and the VAT and other taxes you paid. Spread yearly costs such as trade-licence renewals, visas and insurance across the year.
- 3
Work out your monthly cash in
Average the customer payments you actually received over the same three months. Invoices you've sent but not been paid for don't count yet.
- 4
Subtract to get net burn
Net burn = monthly cash out − monthly cash in. If the answer is zero or negative, you're not burning cash.
- 5
Divide cash by net burn
Runway in months = cash today ÷ net burn. Add the months to today's date to see when the cash runs out.
What is the difference between gross burn and net burn?
| Measure | Formula | What it tells you |
|---|---|---|
| Gross burn | Total cash out per month | How fast you spend, and how long you'd last if revenue stopped |
| Net burn | Cash out − cash in per month | How fast your cash is actually shrinking; use this for runway |
| Runway | Cash today ÷ net burn | Months until the cash reaches zero at today's pace |
Worked example in AED (UAE)
A Dubai software startup
Cash in the bank: AED 900,000. Cash out each month: AED 135,000. Cash in each month: AED 60,000. Net burn = 135,000 − 60,000 = AED 75,000 a month. Runway = 900,000 ÷ 75,000 = 12 months. These are the calculator's starting numbers.
On gross burn alone, the same company would have 900,000 ÷ 135,000 = 6.7 months. That's the worst case if every customer stopped paying, and it shows how much the AED 60,000 of revenue is worth to the runway.
Worked example in SAR (Saudi Arabia)
A Riyadh startup after a seed round
Cash in the bank: SAR 2,400,000. Cash out each month: SAR 260,000. Cash in each month: SAR 110,000. Net burn = 260,000 − 110,000 = SAR 150,000 a month. Runway = 2,400,000 ÷ 150,000 = 16 months.
If that revenue grows 5% a month while costs stay flat, revenue overtakes costs in month 19 and the cash never runs out. At 8% a month, it breaks even in month 13. Try both in the calculator's optional growth fields.
What does “default alive” mean?
The term comes from Paul Graham's essay Default Alive or Default Dead?. A startup is default alive if, with its current revenue growth and costs, it reaches profitability on the money it already has. If not, it is default dead and must raise money, cut costs or grow faster.
| Revenue growth per month | Result |
|---|---|
| 0% | Cash runs out after 12 months |
| 3% | Cash runs out after about 14.8 months |
| 4% | Cash runs out after about 18.6 months |
| 5% | Default alive: revenue overtakes costs in month 18, with about AED 155,000 left at the lowest point |
| 7% | Default alive: revenue overtakes costs in month 13 |
Growth rates are assumptions
A projection is only as good as the growth rate you type in. Use the rate you've actually achieved over the last three to six months, not the one in your pitch deck.
What are the most common runway mistakes?
Check you haven't
- Used a single month instead of a three-month average
- Counted invoices sent instead of cash received
- Left out yearly costs: trade-licence renewal, visas, insurance, audit fees
- Forgotten the VAT you pay to the tax authority each quarter
- Forgotten UAE end-of-service gratuity you'll owe departing staff
- Counted investment that has been promised but not received
How much runway is healthy?
| Runway | What it usually means |
|---|---|
| Under 6 months | Act now: cut costs, collect receivables, or close a round |
| 6–12 months | Start fundraising or plan the path to break-even |
| 12–18 months | A common target straight after a funding round |
| Over 18 months | Room to invest in growth, if burn is going into things that work |
How does ZeroFin Mr. CFO answer runway questions?
This calculator works from the numbers you type in. ZeroFin Mr. CFO, the AI CFO inside ZeroFin, works from your own books instead: ask “What's our runway?” or “What were our top expenses last month?” and it answers from your ledger, covering cash, burn, runway, profit and loss, receivables and payables. You can keep your books in AED or SAR.
| Plan | Price | Mr. CFO questions per month |
|---|---|---|
| Lite | $8 a month (about AED 29 / SAR 30) | 10 |
| Growth | $25 a month (about AED 92 / SAR 94) | 100, plus daily briefings and weekly and monthly reports by email |
| Scale | $50 a month (about AED 184 / SAR 188) | 300 |
Mr. CFO reports what has happened in your books. It doesn't build forecasts or what-if scenarios, so use this calculator for “what if revenue grows 5%?” questions. See ZeroFin in the UAE and Saudi Arabia for what works in the region today.
Frequently asked questions
How do you calculate startup runway?
Divide the cash you have today by your net monthly burn. Net burn is the cash that goes out in a month minus the cash that comes in. For example, AED 900,000 in the bank with AED 135,000 going out and AED 60,000 coming in each month is a net burn of AED 75,000, so the runway is 12 months.
What is a good runway for a startup?
A common rule of thumb is 12 to 18 months after a funding round, and not letting runway fall below about 6 months without a clear plan to raise money, cut costs or reach break-even. Fundraising often takes 3 to 6 months, so start well before the last few months.
Should I use gross burn or net burn?
Use net burn for runway, because revenue you actually collect extends your runway. Look at gross burn too: it shows how long you would last if revenue stopped, which is the worst case.
Should VAT be included in my burn rate?
Use cash. Include VAT you pay to suppliers and the net VAT you pay to the tax authority when you file returns, because both leave your bank account. Count VAT you collect from customers as cash in only until you pay it over. Quarterly VAT payments make some months heavier, so average over at least three months.
What does default alive mean?
A startup is default alive if, at its current revenue growth and costs, it reaches profitability before the cash runs out. If it doesn't, it is default dead and needs to raise money, cut costs or grow faster. Add monthly growth rates in the calculator to check.
Is the calculator free, and are my numbers stored?
It's free and needs no sign-up. The calculation runs in your browser; the numbers you type are not sent to ZeroFin or saved.
Get your runway from your real books
Every new organization gets one free month of the Lite plan. Ask ZeroFin Mr. CFO about cash, burn and runway, answered from your own ledger.