Runway Fundamentals

Startup Runway

The number of months a startup can continue operating before it runs out of cash, based on its current burn rate and available capital.

RunwayCal Mission Control showing runway months, burn rate, and cash-out date

Mission Control shows your runway, burn rate, and projected cash-out date, all computed from your inputs.

What is Startup Runway?

Startup runway is the most critical metric for any founder managing cash. It answers one question: how long can you keep going before the money runs out?

Runway is calculated by dividing your total available cash by your monthly net burn rate. If you have $500,000 in the bank and you're burning $50,000 per month net, you have 10 months of runway.

The number isn't static, it changes every time you hire someone, close a deal, or cut a tool. That's why founders need a system that recomputes runway from current reality, not a spreadsheet frozen in time.

Read more: Startup Runway Guide

Why it matters

Runway determines every major decision a founder makes. When to hire, when to fundraise, when to cut costs, whether to pursue a new market, all of these depend on how many months you have left.

Most founders overestimate their runway because they calculate it once and don't update it as expenses change. A 15-month runway can become 9 months after two hires and a new tool subscription, and many founders don't notice until it's too late.

Formula

Runway (months) = Total Cash / (Monthly Expenses - Monthly Revenue)

Example

A startup has $600,000 in cash. Monthly payroll is $70,000, tools cost $5,000, and commitments are $10,000. Monthly revenue is $25,000. Net burn = $85,000 - $25,000 = $60,000. Runway = $600,000 / $60,000 = 10 months.

How RunwayCal helps

RunwayCal computes your runway in real-time from the team, tools, commitments, and revenue you define. Every time you add a team member or close a deal, your runway number updates instantly. No formulas, no spreadsheet maintenance.

Learn more about the product →

Common mistakes

  • 1Calculating runway once and not updating it as expenses change
  • 2Forgetting to include upcoming expenses like annual tool renewals or planned hires
  • 3Using gross burn instead of net burn, which ignores revenue

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