Free Startup Runway Calculator: You Probably Have Fewer Months of Cash Than You Think

You open your banking app and see ₹1.8 crore. You spend ₹45 lakh a month, collect ₹15 lakh from customers, and the quick maths says you’ve got six months.

Six months sounds survivable. It also isn’t the real number.

Most founders find that out the hard way. Usually it’s month four, and an investor’s “we’re still thinking about it” email is sitting unanswered. The gap between the runway you calculate and the runway you actually have is where startups get into trouble, so let’s close it.

The formula takes ten seconds. The inputs take longer.

Runway is adjusted cash divided by net burn. That’s the whole formula.

Net burn is what you spend each month minus the revenue you actually collect, averaged over the last three months. Adjusted cash is your bank balance after you subtract money that’s already spoken for, like GST and TDS dues or an advance tax instalment.

Here’s an illustrative startup with round numbers (not a real company):

• Bank balance: ₹180 lakh
• Monthly spend: ₹45 lakh
• Revenue collected: ₹15 lakh
• Net burn: ₹30 lakh

The napkin answer is 180 ÷ 30, or 6 months. Now add what the napkin left out. Employer-side payroll costs that never made it into the burn figure add ₹3 lakh a month, so net burn becomes ₹33 lakh. Committed dues of ₹12 lakh bring adjusted cash down to ₹168 lakh.

168 ÷ 33 gives about 5.1 months. Nearly a month disappeared and nobody spent a rupee.

Use three months of data, not one. A festive-season spike or an unusually quiet month will swing the answer. And recalculate every month, as the eChai Ventures guide suggests, not once a year.

The costs your burn figure probably misses

Treelife’s burn rate and runway guide points out that many Indian founders count payroll at CTC and miss the employer’s PF and ESI contributions entirely. Those sit on top of salary:

• PF: the employer pays 12% of basic plus DA, with the wage ceiling at ₹15,000 a month. Add EDLI and admin charges and the all-in cost lands near 13%.
• ESI: the employer pays 3.25% of gross wages for employees earning up to ₹21,000 a month.
• Gratuity: accrues at roughly 4.81% of basic.

PF deposits are due by the 15th of the following month. Late payments attract 12% annual interest plus damages. Treelife notes that some Indian startups have had to put in fresh capital to clear PF arrears before a round could close, which is a bad way to spend a cheque you’ve waited months for.

Revenue has the opposite problem. Booked isn’t banked. ₹50 lakh of annual contracts paid quarterly puts ₹12.5 lakh in your account each quarter, and runway runs on collections.

If you sell products, inventory is cash too. Stock bought ahead of a sale season sits on the shelf, not in your account, so a D2C brand can look healthy on paper while the bank balance thins out.

Read More: How to Raise Startup Funding in India (2026)

Your real deadline isn’t zero cash. It’s the end of your raise.

This is the part that should change how you behave. Open’s guide to extending runway says fundraising in India typically takes four to eight months. Take our illustrative 5.1 months. If the raise runs long, the money is gone before the cheque arrives.

One India-focused runway guide on CalcGuru calls this fundable runway: a company with nine months left has roughly four months in which it can still negotiate from strength. After that, you’re pitching with one eye on payroll. Investors notice, too. Walk into a pitch with four months left and they know you need the deal more than they do.

Advice on when to start varies. eChai Ventures’ founder guide says begin the conversation with six or more months left. Other guides say nine to twelve. We’d go with nine, because a raise that takes the long end of the range still closes with a cushion.

Dunzo shows what waiting looks like. It closed a $240 million round in January 2022, with Reliance Retail putting in $200 million, according to Inc42. Entrackr reported, citing sources, that it later needed follow-on money because only a few months of runway remained. Salaries were delayed. A deal that employees were told in July 2024 was in its final stage never closed, Deccan Herald reported, and the app went offline in January 2025.

Dunzo’s burn was far bigger than any seed-stage startup’s, so don’t read it as a forecast for yours. Read it as the price of counting on a round that hasn’t closed.

Run three versions, not one

A single runway number is a guess dressed up as a fact. Run three:

• Base case: trailing three-month burn and collections, exactly as they are.
• Worst case: collections slip by a month, a key hire starts early, your biggest customer pays late.
• Best case: the pipeline closes on schedule and revenue grows.

Write down the assumption behind each case. “Collections slip by a month” is something you can test. “Things get worse” isn’t. Once the numbers are on a page, a co-founder or advisor can challenge them before an investor does.

Paul Graham’s idea of “default alive” is a useful test. A startup is default alive if its current growth and burn would reach profitability before the cash runs out. If your best case isn’t default alive, the raise isn’t optional. If even your worst case clears nine months, you can afford to be picky about investors.

If the worst case looks too short, you have levers beyond a round. Cancel unused tools, pause hires, chase receivables. Look at non-dilutive money too, starting with government grant schemes for startups in India.

Read More: Government Grant Schemes for Startups in India

And before you give up equity, see what a round costs you. The Funding Round Dilution Calculator shows how each raise changes your ownership. It sits alongside the rest of the free Founder Toolkit.

Start with the number you’ve been avoiding

Pull three months of bank statements. Work out net burn from collections, not invoices. Add the payroll costs your CTC figure hides, subtract what you already owe, and put the result into the Startup Runway Calculator.

Then count back nine months from your zero-cash date and put that day in your calendar. That’s your start line. Update it monthly, because a runway you only check at year-end tells you about a problem after it has already happened.

• Subtract committed dues and add employer payroll costs before you divide. Your real runway is often shorter than the napkin number.
• Fundraising typically takes 4 to 8 months in India, so mark the day you hit nine months of runway as your start line.
• Run base, worst and best cases in the Startup Runway Calculator, then decide whether to raise, cut costs or do both.

Tried it? Tell us in the comments what your real number turned out to be, and share this with a founder who’s still dividing by the bank balance. For more free tools and funding explainers, keep exploring StartupIndiaX.

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