The retention ratio measures how much of a company's earnings stays inside the business — reinvested in growth, debt paydown, or a cash cushion — rather than being paid out to shareholders as dividends. It's the mirror image of the dividend payout ratio, and together the two describe a company's entire earnings-distribution policy.

How the retention ratio works

The retention ratio is calculated as 1 minus the payout ratio, where the payout ratio itself is dividends paid divided by net income. If a company earns $1,000,000 in net income and pays $400,000 in dividends, its payout ratio is 40% and its retention ratio is 60% — meaning $600,000 stays in the business as retained earnings. Net income must be positive for either ratio to make sense; a company with zero or negative earnings can still pay a dividend (funded from cash reserves or debt), but the resulting ratio would no longer represent a genuine split of earnings.

Reading retention as a growth-vs-income signal

A high retention ratio (above roughly 60%) is typical of growth-stage companies — technology firms, biotech, or any business with more attractive internal investment opportunities than it can fund from a modest dividend. A low retention ratio (below roughly 40%) is typical of mature, cash-generative businesses like utilities, REITs, and blue-chip dividend payers, which have fewer high-return reinvestment opportunities and instead prioritize returning cash to shareholders. Neither is inherently better — the right retention level depends on whether the company can actually deploy retained capital at an attractive rate of return.

The link to sustainable growth rate (SGR)

Retention ratio is one of the two inputs to the sustainable growth rate: SGR = ROE × Retention Ratio. This tells you the maximum growth rate a company can support using only its own retained earnings, without issuing new debt or equity. A company with a 15% ROE and a 60% retention ratio has a 9% sustainable growth rate — if it tries to grow faster than that without external financing, it will need to either cut its dividend, take on more debt, or raise fresh equity.

Limits and edge cases

Retention ratio is undefined when net income is zero or negative, since the payout/retention split loses its meaning — this calculator flags that case rather than returning a nonsensical percentage. The ratio also doesn't account for non-cash distributions (stock buybacks are common alternative to dividends and don't appear in this calculation, even though they return cash to shareholders economically). And because retention ratio and SGR both assume current policy holds steady, they're best used as a snapshot of current capital-allocation strategy rather than a precise long-run forecast.