How to Calculate Cash Runway

Track burn and runway so fundraising never becomes reactive.

💰 What is Cash Runway?

Cash runway is the number of months a startup can continue operating before it runs out of cash — assuming current spending levels stay the same.

It helps founders understand how long their company can sustain operations with existing funds, especially when relying on investor capital.

Early-stage startups often operate at a loss while building products and acquiring customers.

The cash runway measures how long that growth phase can continue before new funding is needed.

To calculate your cash runway, you'll need two key metrics:

Burn Rate Basics:

💡 The net burn rate reflects how much cash the company is losing each month after accounting for revenue.

🧾 Cash Runway = Current Cash Balance ÷ Monthly Net Burn Rate

A startup has $250,000 in the bank.

It's spending $90,000 per month and bringing in $20,000 in cash sales.

✅ Cash Runway = $250,000 ÷ $70,000 ≈ 3.6 months

This means the startup will run out of cash in about 3.6 months unless it raises new capital or cuts costs to extend its runway.

There's no universal answer — the ideal runway depends on stage, industry, and growth rate.

That said, most startups aim for 6–12 months of runway. This provides enough time to:

Some investors recommend maintaining 12–18 months of runway to provide extra cushion in uncertain markets.

⚖️ Early-stage startups might get by with less, while established businesses often maintain longer runways supported by detailed forecasts.

If your runway is too short, act early and strategically. Common tactics include:

Cut nonessential spending: Reduce discretionary costs like travel, events, or underused software.
Pause major hires or expenses: Delay new hires or capital purchases until funding is secured.
Speed up collections: Improve invoicing, shorten payment terms, or offer early payment discounts.
Renegotiate terms: Extend payment deadlines or restructure costs with vendors and creditors.

Even small savings can add up, buying crucial time to raise funds or increase revenue.

A cash flow forecast shows how much cash your startup will have in the coming weeks and months.

Without accurate forecasts, it's easy to overspend or miss early warning signs of a shortfall.

Regular forecasting helps you:

Spot potential runway issues early
Run “what-if” scenarios (e.g., delays in fundraising, new hires, pricing changes)
Make faster, informed financial decisions

Updating your forecast regularly ensures your cash runway stays accurate — helping you act before cash becomes critical.