Debt-to-Equity Ratio: When It Works, Misleads, or Breaks

Published: April 20, 2026 · Last updated: August 18, 2026

At Philip Morris International, the March 2026 balance sheet gives D/E of about negative 5.60 times. That result comes from dividing the debt balance by a negative book-equity base. The math is right, but the number does not rank the company beside a positive-equity peer in a useful way.

Philip Morris still had large borrowings, and the negative sign came from negative book equity. A screener may show that figure next to a peer at 2.5 times. The comparison fails because one company has a usable equity base while the other does not.

Before you call a company’s D/E high, low, safe, or dangerous, check the provider’s debt input first. Then make sure book equity still gives the ratio a sound base.

Check What the Numerator Includes

The ratio looks standard, but data providers can use different debt inputs. A capital-structure review often uses interest-bearing borrowings, while some screens use total liabilities. That broader version also includes accounts payable, accrued expenses, taxes payable, and lease liabilities.

Two common leverage calculations that should not be mixed in a peer comparison.

Calculation	Formula	Best Use	Main Limitation
Debt-to-equity	Interest-bearing debt ÷ common shareholders’ equity	Capital structure and financing leverage	Even here, debt definitions can vary
Liabilities-to-equity	Total liabilities ÷ shareholders’ equity	Broad balance-sheet obligations	It mixes financing debt with operating liabilities

Suppose a company has $2 billion of debt, $3 billion of total liabilities, and $1 billion of equity. D/E is 2.0 times, while liabilities/equity is 3.0 times. Both calculations can be valid, but comparing them as if they were the same ratio is not.

This is why the balance sheet matters more than the screener. The SEC’s guide to reading annual reports and filings points to the statements and notes. Those records let you check the debt lines and book equity directly.

Check Whether Equity Can Carry the Ratio

The equity base creates the bigger failure mode. Book equity is what remains after liabilities are subtracted from assets. It can shrink after losses, write-downs, dividends, buybacks, or other comprehensive losses. As that base gets smaller, D/E can surge even when debt barely moves.

How the same $2 billion debt balance changes as book equity approaches and crosses zero.

Debt	Book Equity	Calculated D/E	Interpretation
$2.0 billion	$1.0 billion	2.0×	Comparable when the formula and peer set match
$2.0 billion	$50 million	40.0×	Very sensitive to small denominator moves
$2.0 billion	$0	Undefined	Division by zero
$2.0 billion	−$50 million	−40.0×	The negative sign comes from the denominator

A negative D/E does not sit below 2.0 times on a normal risk ladder because the sign comes from negative book equity. Debt did not reverse, so normal peer ranking should stop until you switch to other credit checks.

No single positive-equity cutoff makes every D/E reliable. Even a small positive equity base can make the ratio unstable, so it helps to sort the result into three broad cases.

A practical three-lane reading without an invented universal percentage threshold.

Equity Condition	Can You Use D/E?	What Changes
Positive and reasonably stable	Usually, with peer controls	Compare trend, sector, numerator, and reporting date
Positive but thin or falling fast	Only with caution	Small equity changes can dominate the ratio
Zero or negative	No normal peer comparison	Switch to coverage, cash flow, liquidity, and maturity analysis

For S&P 500 evidence on how negative equity can distort screening ranks, see the Q1 2026 balance-sheet stress report. Use that report for cross-company results; this guide focuses on how to read D/E itself.

When Peer Comparison Is Valid

D/E still has a real use when you control the peer set. Before you line up two companies, make sure all five conditions below hold.

1. Both companies report positive book equity for the period you are comparing.
2. Both screens use the same debt definition and a closely matched reporting date.
3. The companies operate in a similar sector and have a broadly similar business model.
4. The figures come from the same period or from filings close enough to compare fairly.
5. The accounting treatment is similar enough that the trend is not just a reporting change.

One more issue is timing. The Financial Accounting Standards Board (FASB) lease rule, Topic 842, requires a lessee to record lease assets and lease liabilities for covered leases. The rule improved what the balance sheet shows. Still, an old filing and a newer filing can look different even when the lease economics changed less; FASB explains the rule here.

For the same reason, read a D/E trend with the filings rather than a chart. If the equity base is moving, the companion ROE analysis needs the same care. A small or negative base can warp that ratio too.

What to Use When D/E Breaks

Once equity is near zero or negative, the question shifts from capital structure to payment ability. Ask whether the company can service and refinance its debt. One common input is earnings before interest, taxes, depreciation, and amortization, but that earnings measure has limits.

Replacement metrics for companies with thin or negative book equity.

Metric	Question It Answers	Watch-Out
Interest coverage	How many times operating profit covers interest expense	One good year can hide cyclicality
Net debt / operating earnings (EBITDA)	How large net borrowings are relative to operating earnings	It breaks when the earnings measure is negative or heavily adjusted
Free cash flow / debt	How much debt recurring cash generation could support or reduce	Working-capital swings and capital spending need context
Debt maturity schedule	When refinancing pressure arrives	A manageable total can still hide a near-term wall
Cash and committed liquidity	How much room the company has before outside financing is needed	Restricted cash and covenant limits can reduce access

These measures work best as a set because strong interest coverage does not erase a near-term maturity wall. Positive free cash flow also cannot make every debt-funded deal safe, so read payment ability and timing together.

Philip Morris International: A Negative D/E Example

Philip Morris International gives a clean example of why a negative D/E needs a second step. Its filing for the period ended March 31, 2026 shows $51.948 billion of debt and a $9.279 billion stockholders’ deficit. Dividing those figures gives about −5.60 times, or −560%, because the equity base is negative.

Philip Morris International balance-sheet lines as of March 31, 2026, in billions of dollars.

SEC Filing Line	Value	Why It Matters
Short-term borrowings	$5.693B	Interest-bearing debt
Current portion of long-term debt	$2.447B	Interest-bearing debt due sooner
Long-term debt	$43.808B	Longer-dated interest-bearing debt
Total interest-bearing debt	$51.948B	Sum of the three borrowing lines
Total liabilities	$76.213B	Broader than financing debt
Philip Morris International stockholders’ deficit	−$9.279B	Negative common-equity denominator
Net earnings, first quarter 2026	$2.582B	Current profitability can coexist with negative book equity

The same filing shows $35.538 billion of reinvested earnings and $35.462 billion as the cost of repurchased stock. It also shows $11.788 billion of other comprehensive losses. Those lines help explain how a profitable company can end up with a stockholders’ deficit, but they do not answer whether the debt is safe.

If you use total liabilities instead of debt, the result is about −8.21 times. That larger negative number still does not rank Philip Morris as safer or riskier than a positive-equity peer. By then, the equity base is already below zero.

Primary source: Philip Morris International quarterly report for the period ended March 31, 2026. Balance-sheet values are reported in millions and converted to billions above.

D/E Reality Check Calculator

This calculator tests the decision rule used in this article. Enter debt and book equity from the same reporting date, using one unit such as millions of dollars. Optional fields can add operating-profit, cash-flow, and net-debt checks. The default debt, liabilities, and equity values reproduce the Philip Morris example above in millions.

What Can Default Research Tell You?

Research on leverage supports caution, but it cannot turn a gap in default probability into an investor’s yearly dollar loss.

Cathcart, Dufour, Rossi, and Varotto studied about six million firm-years in six European countries from 2005 through 2015. The large-firm gap between the highest and lowest leverage quartiles was 1.24 percentage points. For small and mid-sized firms, the gap was 2.87 points. The authors linked the larger small-firm gap to more short-term debt and refinance risk. The accepted paper is available from the University of Reading.

The 2.87-point figure is a firm default-probability gap inside that sample, not a stock-return estimate. Applying it to a $100,000 position as a $2,870 yearly loss would mix two different measures that the paper never joined.

Beaver’s 1966 study gives a narrower lesson because it reviewed several ratios from statements in the five years before failure. It supports looking at more than one ratio over time. It does not prove D/E alone can forecast failure five years ahead; see the original Journal of Accounting Research paper.

Readers who want a broader failure framework can continue with how to assess company bankruptcy risk. That guide reads liquidity, cash flow, profit, and leverage together.

A Quick D/E Check: What Should You Verify?

Use this short sequence before you trust a debt-to-equity ratio from a screener:

1. Open the latest filing: start with the balance sheet and debt note from the same period.
2. Rebuild the debt input: decide whether the screen uses financing debt or all liabilities.
3. Inspect common book equity: note whether it is positive, small, falling fast, zero, or negative.
4. Compare only inside the valid lane: match sector, debt definition, reporting date, and accounting basis.
5. Switch measures when the equity base fails: review coverage, net debt/operating earnings, free cash flow, liquidity, covenants, and maturities.

For a filing walkthrough, use the TheFinSense guide to reading a 10-K without missing the debt notes. The balance sheet gives the ratio, while the notes show what the debt figure actually contains.

Debt-to-Equity Ratio: Frequently Asked Questions

Bottom Line: Check the Inputs Before You Trust D/E

D/E is useful only after its inputs pass inspection. Match the debt definition first, then confirm that book equity is positive enough to give the ratio a sound base. Near zero equity the ratio becomes unstable, and at zero it is undefined. Below zero it no longer ranks leverage in the normal way.

Use D/E for controlled peer comparisons when equity is positive and the formulas match. When the equity base becomes small or negative, stop forcing the ratio to rank peers and move to coverage, cash flow, liquidity, and debt maturities.

Update history

• v2.1
  2026-08-18
  CALCULATOR + LINK UPDATE

  Fixed old links and footer markup, added the D/E calculator, and tightened the peer rule.

• v2.0
  2026-07-18
  MAJOR CORRECTION

  Removed an unsupported loss model and a bad use of default risk, then rebuilt the guide around debt inputs, book equity, and the Philip Morris example.

• v1.0
  2026-04-20
  PUBLISH

  Original article published with the first version of the D/E explainer.