The Turnover Time and the Number of Turnovers

We have seen that the entire time of turnover of a given capital is equal to the sum of its time of circulationand itstime of production. It is the period of time from the moment of the advance of capital-value in a definite form to the return of the functioning capital-value in the same form.

The compelling motive of capitalist production is always the creation of surplus-value by means of the advanced value, no matter whether this value is advanced in its independent form, i.e., in the money-form, or in commodities, in which case its value-form possesses only ideal independence in the price of the advanced commodities. In both cases this capital-value passes through various forms of existence during its circular movement. Its identity with itself is fixed in the books of the capitalists, or in the form of money of account.

As soon as the entire capital-value invested by some individual capitalist in any branch of production whatever has described its circuit, it finds itself once more in its initial form and can now repeat the same process. It must repeat it, if the value is to perpetuate itself as a capital-value and to create surplus-value. An individual circuit is but a constantly repeated section in the life of a capital; hence a period. At the end of the period M ... M' capital has once more the form of money-capital, which passes anew through that series of changes of form in which its process of reproduction, or self-expansion, is included. At the end of the period P ... P capital resumes the form of elements of production, which are the prerequisites for a renewal of its circuit. A circuit performed by a capital and meant to be a periodical process, not an individual act, is called its turnover.

The duration of this turnover is determined by the sum of its time of production and its time of circulation. This time total constitutes the time of turnover of the capital. It measures the interval of time between one circuit period of the entire capital-value and the next, the periodicity in the process of life of capital or, if you like, the time of the renewal, the repetition, of the process of self-expansion, or production, of one and the same capital-value.

Apart from the individual adventures which may accelerate or shorten the time of turnover of certain capitals, this time differs in the different spheres of investment. Just as the working day is the natural unit for measuring the function of labour-power, so the year is the natural unit for measuring the turnovers of functioning capital.

If we designate the year as the unit of measure of the turnover time by T, the time of turnover of a given capital by t, and the number of its turnovers by n, then n = T/t. If, for instance, the time of turnover t is 3 months, then n is equal to 12/3, or 4; capital is turned over four times per year. If t = 18 months, then n = 12/18 = ⅔, or capital completes only two-thirds of its turnover in one year. If its time of turnover is several years, it is computed in multiples of one year.

From the point of view of the capitalist, the time of turnover of his capital is the time for which he must advance his capital in order to create surplus-value with it and receive it back in its original shape.