Selling price-purchase price (cost) = profit profit/purchase price (cost) = profit margin Purchase price (cost) times (1+ profit margin) = selling price.

Profit = cost-selling price profit rate = profit/cost profit. The basic quantitative relationship is: commodity profit = (income)-(cost) or commodity profit = (income) * (profit rate).

Operating profit = main business income-main business cost+other business income-other business cost-operating expenses-management expenses-financial expenses-value-added tax-tax-asset impairment loss+fair value change income-fair value change loss+investment income-investment loss.

Profit rate is the ratio of surplus value to all prepaid capital, and profit rate is the transformation form of surplus value rate, which is another ratio calculated by different methods for the same surplus value. If P' stands for profit rate and c stands for all prepaid capital (c+v), then profit rate P'= M/C = M/(C+V). ?

Profit rate is a relative index reflecting the profit level of an enterprise in a certain period. Profit rate index can not only assess the completion of enterprise profit plan, but also compare the management level between enterprises and in different periods to improve economic benefits. Cost profit rate = profit/cost × 100%, and sales profit rate = profit/sales × 100%.