What Is Return on Equity — Measuring How Hard Your Capital Works

The Efficiency Test

Return on Equity (ROE) measures how effectively a company turns shareholders’ money into profit. It’s one of the first numbers professional fund managers check when evaluating a business.

ROE = Net Income ÷ Shareholders’ Equity × 100

If a company earns $10 million in profit and shareholders have $50 million invested, the ROE is 20%. For every dollar of equity, the business generates 20 cents of profit. That’s a well-run operation.

Why ROE Matters

Think of it like this: you could put your money in a savings account earning 4%, or you could invest in a company. ROE tells you how much return that company generates on the capital it holds. A company with a consistent 25% ROE is compounding capital at a rate most investors can only dream of.

Warren Buffett has long used ROE as a primary filter. He looks for companies that sustain above-average ROE over many years — a sign of durable competitive advantage.

How to Read It

• Below 8%: Generally poor. The company isn’t generating much return on the capital invested. Could be a capital-intensive industry or a struggling business.
• 8–15%: Acceptable for most industries. The company is covering its cost of capital and then some.
• 15–25%: Strong. This is where you find well-managed businesses with genuine competitive advantages.
• Above 25%: Exceptional — but check the debt. Some companies artificially inflate ROE by taking on heavy borrowings, which shrinks equity and makes the ratio look better than it is.

The Debt Trap

Here’s the catch that trips up beginners: ROE can be manipulated by leverage. If a company borrows heavily, shareholders’ equity shrinks relative to assets, and ROE goes up — even if the underlying business hasn’t improved.

A company with 50% ROE and a Debt-to-Equity ratio of 5:1 is not the same as a company with 25% ROE and zero debt. The second is actually more impressive and far less risky. Always check how much debt is propping up the number.

DuPont Breakdown

Professional analysts decompose ROE into three drivers using the DuPont formula:

ROE = Profit Margin × Asset Turnover × Financial Leverage

This tells you whether high ROE comes from fat margins (great), efficient asset use (also great), or heavy borrowing (not great). Two companies can have identical ROE but completely different risk profiles.

Practical Example

Consider a tech company earning $2 billion on $8 billion of equity (25% ROE) versus a bank earning $5 billion on $100 billion of equity (5% ROE). The tech firm is far more efficient with capital. But banks are inherently capital-heavy businesses — so 5% might be decent for a bank while being terrible for a software company. Context is everything.

What to Watch For

The most telling signal is ROE consistency over five or ten years. A single year of high ROE means little — it could be a one-off. But a company that sustains 20%+ ROE through economic cycles is demonstrating genuine staying power. Pair ROE with P/E Ratio and Free Cash Flow to understand whether you’re paying a fair price for that quality.

Key takeaway: Consistent ROE above 15% over many years signals a genuine competitive advantage — but always check the debt level. High ROE fuelled by high leverage is a very different beast from high ROE on a clean balance sheet.