What net burn should I use?

Use a recent trailing-three-month or trailing-six-month average if monthly figures bounce around. For a forecast, use a planned monthly burn that includes upcoming hires and contracts.

What if my company is profitable?

If revenue exceeds expenses, net burn is zero or negative — runway is effectively infinite and the calculator will ask you for a positive burn before calculating. Profitable businesses do not need a runway figure for survival; they track months of cash reserve instead.

How accurate is the zero-cash date?

It is a projection, not a guarantee. The math is simple division, but real-world burn varies. Treat the date as the centre of a range and re-check at the start of each month.

When should I start raising again?

Common rule of thumb: start a serious raise when runway hits 9–12 months. Fundraising itself takes 3–6 months and you want to negotiate from strength, not desperation.

Is the calculator free?

Yes. It is free and runs entirely in your browser — no signup, no logging, no upload.

Runway Calculator

Calculate startup cash runway in months and project the zero-cash date from net burn.

Written by Golam Rabbani, Founder & Lead Engineer

This interactive tool requires JavaScript. Read the formula and worked example below; you can compute the result by hand.

How to use this runway calculator

Enter your current cash on hand (bank balance plus any liquid reserves).
Enter your average monthly net burn (expenses minus revenue per month).
Press Calculate to see runway in months and the projected zero-cash date.
Copy the result for a board update or investor email.
If runway is uncomfortably short, model a lower burn or higher revenue in the Burn Rate Calculator and re-check here.

About this runway calculator

The runway calculator is the single most important number in any cash-funded business: how many months until the bank account hits zero at the current burn rate. Cofounders, boards, and lenders ask for it constantly because every other strategic decision — hiring, raising, cutting — flows from it.

Worked example: $500,000 cash in the bank, $40,000 monthly net burn. Runway = 500,000 ÷ 40,000 = 12.5 months. That is about 1.04 years, meaning if nothing changes, cash zero arrives roughly 12–13 months from today. Adding two new hires at $10k/month each pushes burn to $60k and cuts runway to ~8.3 months — the kind of trade-off the calculator makes immediately visible.

The calculator also makes trade-offs concrete. If you cut two contractors saving $15k/month, burn drops from $40k to $25k and runway extends from 12.5 to 20 months — an extra 7.5 months of breathing room from one decision. Note that runway assumes burn stays flat. Real businesses see burn rise with new hires or marketing, and fall with revenue growth. Re-run the calculator whenever a major commitment changes. Everything runs in your browser.

FAQ

What net burn should I use?: Use a recent trailing-three-month or trailing-six-month average if monthly figures bounce around. For a forecast, use a planned monthly burn that includes upcoming hires and contracts.
What if my company is profitable?: If revenue exceeds expenses, net burn is zero or negative — runway is effectively infinite and the calculator will ask you for a positive burn before calculating. Profitable businesses do not need a runway figure for survival; they track months of cash reserve instead.
How accurate is the zero-cash date?: It is a projection, not a guarantee. The math is simple division, but real-world burn varies. Treat the date as the centre of a range and re-check at the start of each month.
When should I start raising again?: Common rule of thumb: start a serious raise when runway hits 9–12 months. Fundraising itself takes 3–6 months and you want to negotiate from strength, not desperation.
Is the calculator free?: Yes. It is free and runs entirely in your browser — no signup, no logging, no upload.