Sustainable Growth Rate Calculator

Both the sustainable growth rate (SGR) and the internal growth rate (IGR) measure how fast a company can grow without issuing new equity, but they differ in one key assumption about debt.

Internal Growth Rate (IGR):

• Definition — The maximum growth rate achievable using only retained earnings with no external financing whatsoever — no new equity and no new debt.
• Formula — IGR = ROA × b / (1 − ROA × b), where ROA is return on assets and b is the retention ratio.
• Uses ROA because it measures the return on the entire asset base, reflecting what the company can earn without any leverage benefit.
• Always lower than SGR because it doesn't allow the company to maintain its current leverage by taking on proportional new debt as equity grows.

Sustainable Growth Rate (SGR):

• Definition — The maximum growth rate achievable without issuing new equity, while allowing the company to take on additional debt proportionally to keep the debt-to-equity ratio constant.
• Formula — SGR = ROE × b / (1 − ROE × b).
• Uses ROE because it measures the return to equity holders, which incorporates the benefit of financial leverage.
• Higher than IGR because the company can borrow proportionally more as its equity base grows through retained earnings.

Practical example: Consider a company with 10% ROA, 20% ROE (implying 2x leverage), and a 40% payout ratio (60% retention). The IGR would be approximately 6.4%, while the SGR would be approximately 13.6%. The difference comes entirely from the company's ability to maintain its leverage ratio by borrowing more as equity grows.

When to use which: Use IGR when analyzing a company that is actively deleveraging or has limited borrowing capacity. Use SGR for companies with stable capital structures that can maintain their current leverage. On CFA exams, SGR is the more commonly tested metric.

DuPont analysis (also called the DuPont framework or DuPont decomposition) breaks return on equity into three component ratios to reveal where the return is coming from. It was developed by the DuPont Corporation in the 1920s and remains one of the most widely used frameworks in fundamental analysis.

The three-factor DuPont identity:

• Profit Margin (Net Income / Revenue) — Measures operational efficiency: how many cents of profit the company keeps from each dollar of revenue. A company with a 20% profit margin converts $1 of revenue into $0.20 of earnings.
• Asset Turnover (Revenue / Total Assets) — Measures asset efficiency: how many dollars of revenue each dollar of assets generates. A company with 0.8x asset turnover generates $0.80 of revenue per dollar of assets. Higher turnover means the company needs fewer assets to generate revenue.
• Equity Multiplier (Total Assets / Total Equity) — Measures financial leverage: how many dollars of assets the company controls for each dollar of equity. An equity multiplier of 2.5x means the company has $2.50 of assets per $1 of equity, implying $1.50 of debt per dollar of equity.

Multiplied together: Profit Margin × Asset Turnover × Equity Multiplier = ROE. This identity holds by mathematical construction — all intermediate terms cancel out.

Why decomposition matters: Two companies can have the same 20% ROE but achieve it very differently. Company A might have high margins (20%) and low leverage (1.5x), while Company B might have thin margins (5%), high asset turnover (2.0x), and heavy leverage (4.0x). Both produce 20% ROE, but Company A's ROE is higher quality because it's driven by profitability rather than debt. DuPont analysis surfaces this distinction instantly.

The five-factor extension further splits profit margin into tax burden (Net Income / EBT), interest burden (EBT / EBIT), and operating margin (EBIT / Revenue). This is less commonly tested but useful for comparing companies across tax jurisdictions or capital structures.

Since the sustainable growth rate is driven by ROE and the retention ratio, there are two fundamental levers a company can pull to increase its SGR. Through the DuPont lens, ROE itself has three sub-levers, giving management five distinct strategies.

1. Increase the retention ratio (reduce dividends)

• The most direct lever. A company paying 60% of earnings as dividends retains only 40%. Cutting the payout to 30% doubles the retention ratio to 70%, directly boosting SGR.
• Trade-off: Dividend cuts often signal financial stress and can crater the stock price. Companies must weigh higher growth capacity against investor expectations for income.

2. Increase profit margin

• Higher margins mean more net income per dollar of revenue, which raises ROE. Strategies include pricing power, cost reduction, operating leverage (fixed costs spread over more units), and shifting the revenue mix toward higher-margin products.
• Example: A SaaS company transitioning from professional services (low margin) to recurring subscriptions (high margin) will see its profit margin — and therefore its SGR — improve.

3. Increase asset turnover

• Generate more revenue per dollar of assets by improving inventory management, reducing excess working capital, utilizing fixed assets more intensively, or adopting asset-light business models.
• Example: A retailer that turns inventory 8 times per year instead of 6 needs less capital tied up in goods, boosting asset turnover and ROE.

4. Increase financial leverage (equity multiplier)

• Taking on more debt increases the equity multiplier, which mechanically increases ROE and SGR. However, this does not actually improve the SGR, because the SGR formula assumes constant leverage. Increasing leverage is a one-time boost to ROE, not a sustainable improvement.
• Caution: Higher leverage also increases financial risk, interest expenses, and the probability of financial distress. This lever has diminishing returns and increasing danger.

5. Share buybacks

• Repurchasing shares reduces total equity, which increases the equity multiplier and ROE. Like leverage, this can boost the measured ROE without truly improving the underlying business economics.

The quality hierarchy: Improving margins and asset turnover are considered high-quality improvements because they reflect genuine operational improvement. Increasing leverage or cutting dividends are lower-quality because they involve financial engineering rather than value creation.

The sustainable growth rate is a staple of the CFA Level I and Level II curricula, appearing in the financial analysis and equity valuation sections. It is one of the most frequently tested quantitative formulas in financial statement analysis.

Common CFA question formats:

• Direct calculation — Given ROE and the dividend payout ratio (or retention ratio), calculate the SGR. Make sure you can work with both the precise formula (ROE × b / (1 − ROE × b)) and the approximation (ROE × b), and know when the exam expects each.
• DuPont-based questions — Given net income, revenue, total assets, and total equity, first compute ROE via the DuPont identity, then calculate SGR. These multi-step problems are common at Level II.
• Conceptual interpretation — "Company X is growing revenue at 20% while its SGR is 12%. What must the company be doing?" Answer: raising external capital (new equity or increasing leverage).
• SGR vs. IGR comparison — Knowing the difference and when each applies. The CFA Institute specifically tests whether candidates understand the role of leverage in distinguishing the two.
• Sensitivity and what-if — "If the company reduces its dividend payout ratio from 40% to 20%, what happens to the SGR?" These require understanding the relationship between retention ratio and growth.

Common mistakes to avoid:

• Confusing payout ratio with retention ratio — they are complements (sum to 100%).
• Using ROA instead of ROE in the SGR formula (or vice versa for IGR).
• Forgetting to convert percentages to decimals before multiplying.
• Using the simple approximation when the question asks for the precise answer.

Study tip: Practice calculating SGR from both directions — given ROE directly and given DuPont components. The CFA exam tests both and expects speed. This calculator lets you verify your manual calculations instantly.

The SGR model is a useful theoretical framework, but it relies on several simplifying assumptions that rarely hold perfectly in practice. Understanding these limitations is essential for applying the concept correctly in real-world analysis.

Key assumptions and their limitations:

• Constant ROE — The model assumes ROE stays the same as the company grows. In reality, ROE often declines as companies scale because new investments may earn lower returns than existing assets (diminishing returns to scale).
• Constant payout ratio — The model assumes the dividend payout ratio stays fixed. In practice, many companies adjust their dividends based on earnings variability, investment opportunities, and board decisions.
• Constant capital structure — The SGR assumes the debt-to-equity ratio remains unchanged. Companies frequently adjust leverage based on interest rate environments, growth phases, and strategic decisions.
• No new equity — Many growth companies regularly issue equity through stock-based compensation (SBC), secondary offerings, or acquisitions. The SGR model doesn't account for these real-world capital sources.
• Accounting-based — ROE is an accounting metric that can be distorted by share buybacks, goodwill impairments, one-time charges, and differing accounting standards. Cash-based metrics may give a more accurate picture.

When SGR works well: The model is most reliable for mature, stable businesses with predictable earnings, consistent dividend policies, and steady capital structures — think consumer staples, utilities, and established financial institutions.

When SGR is misleading: High-growth tech companies, early-stage businesses, cyclical industries, and companies undergoing significant restructuring. A startup burning cash has a negative ROE and a meaningless SGR. A cyclical company's SGR fluctuates wildly with the cycle.

Best practice: Use SGR as one input among many. It provides a useful benchmark for whether a company's growth ambitions are internally financeable, but it should always be supplemented with cash flow analysis, capital budgeting, and an understanding of the competitive environment.

The sustainable growth rate has a direct and important relationship to discounted cash flow (DCF) valuation, especially when setting the terminal growth rate — the growth rate used to calculate the company's value beyond the explicit forecast period.

Terminal growth rate constraint:

• In a DCF model, the terminal value typically accounts for 60-80% of the total enterprise value. It is calculated using a perpetuity growth formula: Terminal Value = FCF × (1 + g) / (WACC − g), where g is the terminal growth rate.
• The terminal growth rate must be sustainable indefinitely. A company cannot grow faster than its SGR forever without continuously raising capital. Setting the terminal growth rate above the SGR implicitly assumes perpetual capital raises.
• In practice, the terminal growth rate should not exceed nominal GDP growth (typically 2-4%), and it should not exceed the company's long-term SGR. The lower of the two is the appropriate ceiling.

Revenue growth validation:

• During the explicit forecast period (typically 5-10 years), the projected growth rates should be compared to the SGR. Years where growth exceeds the SGR should explicitly model the required financing (new shares issued, higher debt).
• If your DCF projects 12% revenue growth for 10 years but the company's SGR is 7%, the model should show increasing leverage or share count. If neither is modeled, the projections are internally inconsistent.

Reinvestment rate connection: The SGR framework connects directly to the fundamental growth equation used in DCF models: g = Reinvestment Rate × Return on Invested Capital (ROIC). This is conceptually identical to SGR = b × ROE. The reinvestment rate is the fraction of earnings plowed back into the business, and ROIC/ROE is the return earned on that reinvestment.

Bottom line: Understanding SGR makes you a better DCF modeler because it forces you to think about whether projected growth rates are achievable given the company's profitability and capital allocation. A DCF model with internally consistent growth assumptions is far more defensible than one with arbitrary growth rates.

There is no single "good" SGR because the metric depends heavily on industry dynamics, business maturity, and capital allocation strategy. However, comparing a company's SGR to its actual growth rate and to industry peers provides valuable insight.

SGR benchmarks by industry:

• Technology / Software (SGR: 15-30%+) — High ROE driven by strong profit margins and asset-light models. Many tech companies retain 100% of earnings (no dividends), maximizing the retention ratio and SGR. However, actual growth often exceeds SGR because these companies also issue equity through SBC.
• Consumer Staples (SGR: 5-10%) — Moderate ROE with significant dividend payouts (50-70% payout ratios). These mature businesses are not trying to grow faster than their SGR; they prioritize returning capital to shareholders.
• Financials / Banks (SGR: 6-12%) — Banks have high equity multipliers (10x+) which inflates ROE, but they also pay meaningful dividends. The SGR tends to be in line with nominal GDP growth plus some spread.
• Utilities (SGR: 3-6%) — Low-growth, high-payout businesses with regulated returns. Their SGR matches their growth expectations because they consistently issue new equity and debt to fund capital investment.
• Healthcare / Pharma (SGR: 8-15%) — Strong margins offset by moderate asset turnover. SGR varies significantly between high-growth biotech (low/no dividends, high SGR) and mature pharma (high dividends, moderate SGR).

What to watch for:

• Actual growth above SGR — If a company consistently grows faster than its SGR, look for rising leverage, equity issuance, or increasing SBC dilution. At least one of these must be happening.
• Actual growth below SGR — The company is retaining more earnings than it can productively reinvest. This usually leads to share buybacks, special dividends, or acquisitions — some of which may destroy value.
• Declining SGR — A falling SGR signals deteriorating profitability or increasing payouts. If ROE is dropping, dig into DuPont components to understand whether it's a margin, efficiency, or leverage issue.