If you run a startup, there are two numbers you should be able to recite in your sleep: your burn rate and your runway. These aren't just metrics for investor presentations — they are the difference between making a pivot in time and running out of money before you can.
In this guide, we'll break down exactly how to calculate both, what healthy numbers look like at different stages, and the early warning signs every founder should act on immediately.
Burn rate is the rate at which your startup is spending its cash reserves. It comes in two flavours:
Most early-stage startups focus only on gross burn. This is a mistake. Net burn tells you the real speed at which you're depleting your capital — and it's the number VCs will ask for first.
Runway is the number of months your startup can operate before running out of cash, at your current burn rate. It's the answer to the question: "How much time do we have?"
Runway (months) = Cash in Bank ÷ Net Burn Rate If you have ₹60,00,000 in bank and burn ₹5,00,000/month → Runway = 12 monthsThe general rule of thumb in the startup world is to always maintain a minimum of 12–18 months of runway. Here's why:
At Hawkfin, we recommend founders start fundraising conversations when they have at least 9 months of runway remaining — not 3.
If your monthly expenses are growing month-on-month but revenue isn't keeping pace, your runway is shrinking faster than your projections show. This is the most common trap early-stage founders fall into.
At 6 months, you've crossed into emergency territory. You no longer have time to run a proper fundraising process — which means you'll either take a bad deal or raise at poor terms.
Can you cut 20% of costs if you needed to? Is there a revenue lever you can pull quickly? If the answer is no, you're fragile. Build these options before you need them.
This is often hidden in the numbers. Hiring more people doesn't always mean more output. If your revenue per employee is declining quarter-on-quarter, your burn rate is becoming structurally unsustainable.
The best financial models assume the worst. If your runway calculation depends on closing a specific deal, hitting a specific growth target, or launching on schedule — stress test those assumptions now.
📊 Hawkfin TipRun three scenarios every month: Base case (current trajectory), Downside (20% revenue miss), and Stress test (no new revenue for 3 months). Know your runway in each one.
There are only three levers: increase revenue, reduce burn, or raise more capital. In practice, the fastest and most controllable is reducing burn — but not all expenses are equal.