What Is Capital Structure? Types and Examples

By Markets & Investing DeskUpdated Nov 10, 2026

Definition

Capital structure is the mix of debt and equity a company uses to fund its assets, operations and growth, and it shapes the company's risk, cost of funding and flexibility.

Key takeaways

Interest on debt is generally tax-deductible while dividends are not, which lowers the effective cost of debt.
Debt-to-equity divides total debt by shareholders' equity, so a D/E of 2.0 means borrowing twice what owners put in.
In the article's example, raising debt from $40M to $60M lifts return on equity from 13.3% to 17.5% at a 10% asset return.
Utilities often carry heavy debt because regulated, predictable cash flows can reliably service the interest.

Capital structure is the mix of debt and equity a company uses to finance its assets, operations and growth. It shows how much of the company’s funding comes from lenders, who must be repaid with interest, and how much comes from owners, who share in whatever profit is left. That mix shapes a company’s risk, its cost of funding and how much room it has when conditions turn against it.

What capital structure includes

In corporate finance, capital structure refers to a company’s long-term sources of funding. The common parts are:

Senior debt: bank loans and bonds that are repaid first if the company fails, often secured by specific assets.
Subordinated (junior) debt: borrowing that ranks behind senior debt in repayment and usually pays a higher interest rate to compensate.
Hybrid securities: instruments such as convertible bonds, which start as debt but can turn into shares.
Preferred equity: shares that typically receive fixed dividends and rank ahead of common shareholders, but behind all creditors.
Common equity: money raised by selling shares plus retained earnings, the profits the company has kept rather than paid out.

Ordered from first-paid to last-paid, these layers form what is often called the capital stack. The stack and the capital structure describe the same funding sources: the structure focuses on proportions (how much of each), the stack on priority (who gets paid first).

How capital structure works

Each source of capital comes with a different deal. Lenders accept a capped return, the agreed interest, in exchange for a contractual claim on cash flow and priority in bankruptcy. Shareholders accept no guaranteed payment in exchange for ownership and an unlimited share of the upside.

That difference produces the central trade-off.

Why companies borrow:

Interest payments are generally tax-deductible, while dividends paid to shareholders are not. This “tax shield” lowers the effective cost of debt.
Borrowing does not dilute ownership or voting control.
If the company earns more on borrowed money than it pays in interest, the surplus goes to shareholders, raising return on equity.

Why companies prefer equity:

There are no required payments. A company can cut or skip dividends when business slows.
Lower debt means lower bankruptcy risk and more flexibility in a downturn.
Lenders often attach covenants that restrict how a borrowing company operates; equity does not.

The fixed nature of debt is what makes it dangerous. When air travel stopped in 2020, airlines still owed interest on their borrowings while revenue collapsed. Even cash-rich firms borrow strategically: in August 2024 Meta Platforms raised $10.5 billion in debt while holding roughly $58 billion in cash and equivalents, to help fund data centers and AI infrastructure.

How to measure capital structure

Three ratios do most of the work:

Debt ratio = Total debt ÷ Total assets
Debt-to-equity (D/E) = Total debt ÷ Shareholders’ equity
Debt-to-capital = Total debt ÷ (Total debt + Shareholders’ equity)

Definitions of “total debt” vary. Some analysts use only interest-bearing borrowings; others add lease obligations. When comparing two companies, use the same definition for both.

Example of capital structure

Hypothetical example. Company A has $100 million in total assets, funded by $40 million of interest-bearing debt and $60 million of shareholders’ equity (assume no other liabilities).

Debt ratio: $40M ÷ $100M = 40%
D/E: $40M ÷ $60M = 0.67
Debt-to-capital: $40M ÷ ($40M + $60M) = 40%

Now suppose Company A borrows $20 million and uses it to buy back $20 million of stock. Debt rises to $60 million and equity falls to $40 million, so D/E jumps from 0.67 to 1.5. Total assets did not change; only who owns the claims on them did.

The leverage effect works both ways. Assume Company A earns a 10% return on its $100 million of assets ($10 million before interest) and pays 5% interest, ignoring taxes:

Structure	Interest	Profit to equity	Return on equity
$40M debt / $60M equity	$2M	$8M	13.3%
$60M debt / $40M equity	$3M	$7M	17.5%

If asset returns fall to 3%, the same two structures produce returns on equity of 1.7% and negative 0.75%. More debt magnifies both good and bad results.

Interpreting the ratios

A D/E of 2.0 means the company has borrowed twice what shareholders have put in. Whether that is high depends on the business. Utilities typically carry heavy debt because regulated, predictable cash flows can reliably service it, and their power plants and grids need large amounts of long-term capital. Early-stage technology companies and commodity producers have volatile revenue, so they tend to keep debt low because a bad year could leave them unable to pay interest. Apple had no long-term debt in the early 2010s and funded itself from retained earnings before it began issuing bonds.

Theories behind capital structure decisions

Several established frameworks explain how companies choose their mix:

Modigliani-Miller (1958): in an idealized market with no taxes, bankruptcy costs or information gaps, capital structure does not affect a firm’s value. The theorem matters because it shows that real-world effects come from taxes, distress costs and other frictions.
Trade-off theory: a company adds debt until the extra tax benefit is offset by the rising expected cost of financial distress. This implies an optimal, or target, capital structure.
Pecking order theory: companies prefer internal funds first, then debt, and issue new equity last, partly because selling shares can signal that management thinks the stock is overvalued.

The target structure is the mix a company aims to hold over time. Firms that drift away from it, for instance after a large acquisition funded with debt, may rebalance by issuing shares, paying down borrowings or changing their dividend policy.

Why capital structure matters

Capital structure feeds directly into valuation. The weights of debt and equity determine a company’s weighted average cost of capital (WACC), the discount rate used in a discounted cash flow model. A cheaper overall cost of capital raises the present value of future cash flows, up to the point where extra debt raises the cost of both debt and equity enough to offset the gain.

It also matters in acquisitions. A buyer acquires the whole capital structure, which is why enterprise value adds debt to the market value of equity and subtracts cash. For investors, the mix signals how much of a company’s earnings is already committed to lenders and how exposed shareholders are if results weaken.

Capital structure vs. financial structure: financial structure covers all of the liabilities and equity on the right side of the balance sheet, including short-term items like accounts payable. Capital structure usually focuses on long-term debt and equity.
Capital structure vs. capital allocation: capital structure is about where money comes from; capital allocation is about where management spends it (investment, acquisitions, dividends, buybacks).

Limitations of capital structure analysis

Book vs. market values: balance sheet equity can differ sharply from market capitalization. A company with large buybacks can show negative book equity while its shares are worth billions, making book-based D/E misleading.
Snapshot timing: ratios reflect one reporting date and can shift after a single bond issue or acquisition.
Hidden obligations: leases, pension deficits and guarantees may not be captured by a simple debt figure.
No cash flow view: a ratio shows how much debt exists, not whether the company can pay it. Coverage measures such as interest coverage fill that gap.

FAQs

Should analysts use the current or target capital structure?

For valuation and for relevering beta, analysts generally use the target capital structure, because the discount rate should reflect the financing mix the company expects to maintain over the forecast period. The current mix is used when it is expected to persist or when no reliable target is known.

The Bottom Line

Capital structure matters to investors, analysts and managers because it sets how much of a company's earnings is already owed to lenders. More debt can raise shareholder returns and cut funding costs, yet it also magnifies losses and bankruptcy risk when results weaken. Judge leverage against the company's industry, use consistent debt definitions, and pair balance sheet ratios with cash flow measures such as interest coverage.