Free calculator
Free startup runway calculator
Runway is the number of months before your bank balance hits zero. Enter your cash, current revenue and costs, and how fast revenue grows, to see how long you can keep operating at this trajectory.
Last updated: September 2026
How long until the money runs out
= Rs. 1.2M
= Rs. 150k
= Rs. 400k
- Net burn today
- Rs. -250,000.00
- Runway
- 5 months
- Cash in 12 months
- Rs. -1,800,000.00
How the formula works
Runway = months until cumulative (revenue minus costs) exhausts starting cash. With flat burn it is simply cash divided by monthly loss. With growing revenue the shortfall shrinks each month, so runway extends beyond what a static calculation suggests.
Worked example
You hold Rs. 1.2 million, spend Rs. 400,000 a month and earn Rs. 150,000, so net burn is Rs. 250,000. A static view says under five months. With 8 percent monthly revenue growth, runway stretches past seven months, which may be the difference between raising calmly and raising in a panic.
How to use the calculator
- Step 1 - Enter cash on hand
The amount currently in the bank accounts you can spend on operations, not receivables you have not collected.
- Step 2 - Enter monthly revenue and monthly costs
Use realistic averages. The difference between them is your net burn - negative burn means you extend runway every month.
- Step 3 - Set monthly revenue growth
A percentage such as 8% compounds each month and shrinks the shortfall, pushing runway beyond the static cash-divided-by-burn estimate.
- Step 4 - Read the runway
The result shows net burn today, months before cash hits zero, and your cash balance 12 months out. Under 12 months means prioritising fundraising or cost cuts.
What affects the result
Your runway is driven by the current cash balance, the gap between revenue and costs each month, and how quickly revenue grows. Cash-in timing matters too: if customers pay on 60-day terms, receipts lag the sales counted here. One-off outflows such as annual licences, tax payments or equipment purchases shorten runway in a specific month, month-by-month cash flow projection captures those spikes.
Common mistakes
- Using average burn that hides upcoming hires or annual renewals.
- Assuming growth without checking where new customers come from.
- Forgetting founder salary; unpaid founders make runway look longer than it is.
- Raising money when runway is already under three months; fundraising takes longer than that.
Frequently asked questions
How much runway should I aim for?
At least 12 to 18 months if you plan to raise funding, since fundraising itself consumes three to six months of attention.
Does revenue growth really extend runway?
Yes, as long as growth does not require proportional spending increases. Growth bought with equal spending leaves burn unchanged.
What is the fastest way to extend runway?
Cut fixed costs, collect receivables faster, or delay discretionary spending. All three act immediately on the balance.
What is the startup runway formula?
With flat spending, runway in months equals cash on hand divided by monthly net burn (expenses minus revenue). If you burn Rs. 250,000 a month from Rs. 1.2 million in the bank, runway is 1,200,000 / 250,000 = 4.8 months.
What is a healthy burn rate?
A common target is keeping burn low enough to leave 12-18 months of runway. For pre-revenue startups, monthly burn of roughly 5-10% of total funding is common early on.
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Results are arithmetic on the numbers you enter, not predictions. Validate important figures with an accountant before making financial commitments.