If you run a startup, there are two financial metrics you should review regularly: Burn Rate and Runway.

These metrics help you understand how quickly your company is using cash, how long it can continue operating with its available resources, and, above all, how much time you have to make decisions before liquidity or financing pressures emerge.

Many founders focus their attention on sales, growth, or the next funding round. However, the reality is that financial problems often begin long before they become obvious. Burn Rate and Runway help identify early signs of financial distress and allow businesses to take action while there is still room to manoeuvre.

In this article, we explain what these metrics mean, how to interpret them and why they can become a key tool for protecting a startup’s long-term sustainability

Is Your Startup Burning Cash Faster Than Expected?

Imagine a tech startup that has just closed a €1 million funding round.

With these new resources, the team decides to accelerate growth by hiring new sales professionals, strengthening product development and increasing marketing investment. The initial results appear promising. Revenue grows, new customers come on board and the outlook is positive.

However, as the business develops, cash begins to disappear faster than expected. Every month, the company requires more resources to sustain its growth rate and, almost without realising it, has less time available to achieve its objectives.

This situation is far more common than many founders realise. And this is precisely where two of the most important metrics for any startup come into play: Burn Rate and Runway.

Burn Rate: The Speed at Which You Burn Cash

Burn Rate measures the pace at which a startup consumes cash to fund its operations.

Formula: Monthly Burn Rate = Monthly Cash Outflows – Monthly Cash Inflows

In simple terms, it shows you how much money leaves the bank account each month after accounting for the revenue generated by the business.

A high Burn Rate is not necessarily bad news. Many startups invest aggressively in product, talent acquisition or market expansion during their early stages because they prioritise growth over short-term profitability.

The problem arises when that level of spending is no longer supported by a clear strategy, or when funding prospects begin to deteriorate. At that point, every euro spent reduces the company’s ability to react if things do not go according to plan.

Runway: The Time Left to Make Decisions

If Burn Rate measures speed, Runway measures time.

Formula: Runway = Cash Available / Monthly Burn Rate

This metric calculates how many months the company can continue operating while maintaining its current rate of cash consumption.

Returning to the previous example, if the startup has €1 million in cash and burns €100,000 per month, it has approximately 10 months of Runway.

However, if a few months later it decides to expand its workforce, strengthen its sales team and accelerate certain investments, its monthly Burn Rate may increase to €150,000. Even if the company continues to grow, the time available to react will have been significantly reduced.

And that is the key point: many startups remain focused on growth while the real issue lies in how quickly their room for manoeuvre is shrinking.

The Most Important Metric Is Not the Number Itself, but the Trend

One of the most common mistakes founders make is analysing these metrics in isolation.

What truly matters is understanding how they evolve over time.

A steadily increasing Burn Rate without a corresponding improvement in business performance, or a Runway that shortens month after month, are often warning signs that deserve close attention. Not because they necessarily indicate an imminent crisis, but because they reveal that the company has less and less time to correct potential problems.

In our experience, many startups seek professional advice only when they have a few months of cash remaining or when an anticipated funding round fails to materialise. However, identifying risks earlier is far more effective, while strategic alternatives are still available.

When Should a Startup Be Concerned About Its Burn Rate?

There is no universal figure that applies to every startups. A high Burn Rate can be perfectly reasonable during a period of rapid growth or expansion.

What matters is analysing the combined evolution of Burn Rate, Runway and the company’s actual ability to achieve its business objectives or secure new sources of funding.

Some warning signs that deserve particular attention include:

▸ A constant increase in cash burn.
▸ Delays in expected funding rounds.
▸ Excessive dependence on external financing to maintain operations.
▸ A rapid reduction in Runway.
▸ Growing tensions with suppliers or creditors.
▸ Recurring delays in payment obligations.
▸ Rising costs without a corresponding increase in revenue.
▸ Limited visibility over future cash flow.

Identifying these situations at an early stage allows founders and management teams to evaluate alternatives and take action while there is still scope to do so.

When Your Room for Manoeuvre Begins to Shrink

If these metrics start to show a negative trend, decisions relating to funding, investors, creditors and corporate structure begin to have a direct impact on the company’s continuity.

Experience shows that most business crises do not emerge overnight. In many cases, there are early indicators that allow companies to anticipate problems, reassess their funding strategy, explore restructuring alternatives and implement measures aimed at protecting both the business and its directors.

Acting at the right time does not always prevent difficulties, but it significantly increase the options available to manage them effectively.

Anticipating Is the Best Way to Protect a Startup

Understanding and monitoring Burn Rate and Runway is not simply about tracking two financial indicators. In reality, it means understanding how much room for manoeuvre a startup has to adapt, correct course and make informed strategic decisions.

The sooner the first signs of financial distress are detected, the greater the likelihood of preserving company value, protecting founders and directors, and safeguarding the long-term viability of the project.

At AGM Abogados, we advise startups, founders and investors facing financial challenges, helping them identify risks, assess available options and make informed decisions while there is still time to act.

If you would like to learn more about our approach to supporting startups facing financial difficulties or restructuring processes, visit AGM Abogados’ Legal Advisory Services for Startups in Crisis page.