How retained profit sets a company’s growth ceiling
Every dollar of profit a company earns goes one of two ways: out the door as a dividend, or back into the business as retained earnings. Only the retained portion can fund new assets, and new assets are what let sales and profits grow. So the rate at which a firm can grow on its own is set by how much it earns on its equity (return on equity) and how much of that it keeps (the retention ratio). Multiply the two and you get the sustainable growth rate — the pace at which equity, and the business it supports, can compound without any outside money. Grow slower and cash piles up; grow faster and you must raise it from lenders or shareholders. You can decompose the ROE side further with our ROE calculatorand inspect the reinvestment side with theretention ratio calculator.
The sustainable growth formula
SGR = ROE × Retention ratio
Retention ratio = 1 − Dividend payout ratio
where ROE is net income divided by shareholders’ equity and theretention ratio (also called the plowback ratio) is the share of earnings kept rather than paid out. The model holds ROE, payout, and capital structure constant, so the SGR is the growth rate retained earnings can finance entirely on their own.
What makes this calculator different
- One number that ties it all together. It combines return on equity and the retention ratio into a single growth ceiling, so you can see exactly how profitability and reinvestment policy interact.
- The implied payout, shown. Set a retention ratio and the calculator surfaces the dividend payout it implies (1 − retention), so the trade-off between paying shareholders and funding growth is explicit.
- The financing implication, spelled out. It makes clear that any growth above the SGR has to be funded by new debt or new equity, turning an abstract ratio into a practical test of whether a growth plan is self-financeable.
Frequently asked questions
What is the sustainable growth rate and how is it calculated?+
The sustainable growth rate (SGR) is the maximum pace at which a company can grow its sales and earnings using only internally generated funds — that is, profits it keeps rather than pays out. The formula is simple: SGR = ROE × retention ratio, where return on equity measures how much profit each dollar of equity earns and the retention ratio is the fraction of those profits reinvested. Multiply the two and you get the rate at which equity, and the business it supports, can compound on its own. It is a clean way to express how profitability and reinvestment policy combine into a single growth ceiling.
Why does growing faster than the SGR require outside financing?+
The SGR is, by construction, the growth rate that retained earnings alone can fund while holding the capital structure fixed. If a company wants to grow faster than that, the extra assets needed to support the higher sales cannot be paid for out of reinvested profit — there simply is not enough. That gap has to be filled from outside the business: either new debt, which raises leverage, or newly issued equity, which dilutes existing shareholders. So exceeding the SGR is not impossible, it just means the firm is choosing to change its financing mix rather than grow purely from within.
What is the retention (plowback) ratio?+
The retention ratio, also called the plowback ratio, is the share of net income a company keeps and reinvests rather than distributing to shareholders as dividends. It is the mirror image of the dividend payout ratio: retention ratio = 1 − dividend payout ratio. A firm that pays out 30% of earnings retains 70%, giving a retention ratio of 0.70. The higher the retention ratio, the more profit is recycled back into the business to fund growth, which directly raises the sustainable growth rate.
How can a company raise its sustainable growth rate?+
Because SGR depends on ROE and the retention ratio, a company has several levers. It can lift profit margins so each sale generates more earnings, improve asset turnover so it squeezes more revenue out of its asset base, or take on more leverage so equity is stretched across a larger balance sheet — these three together are the DuPont drivers of ROE. Alternatively, it can simply retain a larger share of earnings by cutting the dividend, raising the retention ratio. Each route increases how fast the firm can expand without tapping external capital.
What are the limitations of the sustainable growth model?+
The model is a useful approximation, not a forecast. It assumes return on equity, the dividend payout, and the capital structure all stay constant, which rarely holds for long — margins drift, payout policy changes, and leverage ratios move with the business cycle. It also ignores one-off events, changing reinvestment opportunities, and the fact that a maturing company often cannot keep earning the same ROE on ever-larger amounts of capital. Treat the SGR as a benchmark for whether a growth plan is internally financeable, not as a precise prediction of future growth.
Disclaimer: This calculator is foreducation and illustration only. The sustainable growth rate is a model built on simplifying assumptions (constant return on equity, payout ratio, and capital structure); its output is a benchmark, not a forecast, and a real company’s growth will differ. Nothing here is investment, tax, or trading advice.