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. Profit margin is usually expressed as a percentage. Cost profit rate = profit/cost × 100%, and sales profit rate = profit/sales × 100%.

Common methods for calculating profit rate

1, special value method. In general, the unknown quantity cost is set to a special value, namely 1 or 100.

2. Proportional method. According to the formula "selling price = cost ×( 1+ profit rate)", when the selling price is fixed, the cost is inversely proportional to (1+ profit rate).

3. Equation method. The key is to find equivalence relation.

4. Cross method. The mixed problem of profit rate is similar to the mixed problem of concentration.

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.

Derivation process of profit rate formula: operating profit = main business income-main business cost-main business tax and surcharge+other business income-other business expenses-operating (sales) expenses-management expenses-financial expenses. Total profit = operating profit+subsidy income+non-operating income-non-operating expenditure. Net profit = total profit-income tax.