Interest Coverage Ratio
Interest coverage measures a company's ability to service its debt from operating earnings. The most direct measure of debt sustainability.
Interest Coverage Ratio Explained
Interest coverage measures how easily a company can pay the interest on its outstanding debt from its operating earnings. It's the most direct test of debt sustainability and arguably more important than debt-to-equity, because what ultimately matters is whether the business can service its obligations, not how much debt is on the balance sheet relative to equity.
What it measures
The formula:
Interest Coverage = EBIT ÷ Interest Expense
EBIT is operating income (earnings before interest and taxes). Interest expense is what the company pays on its debt obligations annually. The result is the number of times operating earnings cover required interest payments.
An interest coverage of 5x means operating earnings are five times required interest payments. The company could see operating income fall 80% before it would struggle to service debt.
If $AAPL generates $117B in EBIT against $4B in interest expense, interest coverage is roughly 29x. Apple could lose more than 95% of its operating earnings before debt service became stressed.
A variant uses EBITDA instead of EBIT:
EBITDA Interest Coverage = EBITDA ÷ Interest Expense
This is more generous because it adds back depreciation and amortization. For capital-intensive businesses, EBITDA coverage is often the more relevant measure because depreciation isn't an actual cash outflow that competes with interest payments.
How to use it in practice
Interest coverage benchmarks for healthy businesses:
- Investment grade (BBB+ and above): 8x+
- Investment grade lower (BBB to BBB-): 4-8x
- High yield (BB): 2.5-4x
- Distressed (below B): Below 2x
The trend matters significantly. A business with deteriorating interest coverage is heading toward credit stress, even if absolute levels still look acceptable. Conversely, a business deleveraging or growing earnings faster than interest expense is improving credit quality.
The combination of interest coverage and debt-to-equity gives a complete picture of financial risk. A company with debt-to-equity of 1.5 and interest coverage of 8x is in much better shape than one with debt-to-equity of 0.8 and interest coverage of 2x. The first is leveraged but comfortably servicing; the second is less leveraged but more stressed.
For cyclical businesses, interest coverage at the bottom of the cycle is the relevant test, not the average. A commodity producer with 8x average coverage that drops to 1.5x at the trough faces real refinancing risk during downturns.
Common mistakes
Using current interest coverage to evaluate companies entering a downturn. What matters is what coverage will look like at the trough of the cycle, not the current peak.
Ignoring debt maturity profile. A business with comfortable interest coverage but a wall of debt maturing in 18 months still faces refinancing risk if credit markets tighten.
Comparing interest coverage across rate environments. Coverage looked stronger when rates were near zero. As floating-rate debt resets and refinancing happens at higher coupons, coverage compresses even when operating earnings are stable.
ACCE perspective
We track interest coverage in our financial models for every curated stock with meaningful debt. The metric is particularly important for cyclicals, capital-intensive businesses, and any company we identify as having balance sheet sensitivity.
For investors evaluating financial strength, the combination of interest coverage above 5x and debt-to-EBITDA below 3x is a reasonable threshold for credit comfort across most sectors. Below these levels, balance sheet risk becomes a meaningful consideration in any equity thesis.