Why defensive interval ratio matters to a first-time founder
This ratio gives a short-term resilience check using assets that can readily fund operations. Unlike a sales forecast, it asks how long the company could keep paying ordinary costs if cash receipts stopped. A shrinking interval can expose a financing need before the bank balance becomes critical.
Examples of defensive interval ratio
A company has $180,000 of cash, marketable securities and receivables, with annual operating expenses of $730,000 after non-cash charges. Average daily cash costs are $2,000, so the defensive interval ratio is 90 days. Collection delays could make the practical interval shorter.
Common misunderstanding
It is not identical to cash runway. The defensive interval ratio normally includes selected liquid assets, such as receivables, while a simple runway often divides available cash by monthly net cash burn. Definitions vary, so state which assets and expenses you included before comparing companies.
When to use it
Use it during monthly cash reviews, downside planning or lender discussions when revenue may be interrupted. It is most useful beside a cash forecast that reflects payment timing. Ignore headline comparisons unless the calculation method matches, and investigate falling coverage rather than treating one threshold as universal.