Rate of profit

From Freepedia

In economics, the profit rate refers to the relative profitability of an investment project or of an capitalist enterprise or for the capitalist economy as a whole. It is similar to the idea of the rate of return on investment.

In Marxian political economy, the rate of profit (r) would be measured as

r = (surplus-value)/(capital invested).

where surplus-value corresponds to unpaid labor in the production process or to profits, interest, and rent (property income).