(real rate of surplus-value × variable capital advanced × n) / (variable capital advanced)
For instance, in the case of capital B = 100 × 5,000 × 1 / 5,000 , or 100%. Only when n is equal to 1, that is, when the variable capital advanced is turned over only once a year, and hence equal to the capital employed or turned over during a year, the annual rate of surplus-value is equal to its real rate.
Let us call the annual rate of surplus-value S', the real rate of surplus-value s', the advanced variable capital v, the number of turnovers n. Then S' = s'vn/v = s'n. In other words, S' is equal to s'n, and it is equal to s' only when n = 1, and hence S' = s' times 1, or s'.
It follows furthermore that the annual rate of surplus-value is always equal to s'n, i.e., to the real rate of surplus-value produced in one period of turnover by the variable capital consumed during that period, multiplied by the number of turnovers of this variable capital during one year, or (what amounts to the same) multiplied by its inverted time of turnover calculated for one year. (If the variable capital is turnover over ten times per year, then its time of turnover is 1/10 of a year; its inverted time of turnover therefore 10/1 or 10.)
It follows furthermore that S' = s' when n is equal to 1. S' is greater than s' when n is greater than 1; i.e., when the advanced capital is turned over more than once a year or the turned-over capital is greater than the capital advanced.
Finally, S' is smaller than s' when n is smaller than 1, that is, when the capital turned over during the year is only a part of the advanced capital, so that the period of turnover is longer than one year.
S' = s'n indicates that the rate of surplus-value valid for the variable capital employed during one period of turnover, to wit,
(quantity of s produced in one turnover period) / (variable capital employed in one turnover period)
must be multiplied by the number of turnover periods, or of the periods of reproduction of the advanced variable capital, by the number of periods in which it renews its circuit.