Expansion: The concept of "gross profit margin" is based on the concept of "gross profit". Gross profit is the symmetry of "net profit", also known as "price difference between commodity purchase and sale", which is the balance of commodity sales income MINUS commodity purchase price.
Net profit/net profit in a specific period = gross profit in this period-related expenses in this period (including depreciation) = (sales revenue-cost of sales)/sales revenue × 100%.
Non-agricultural products are purchased from general taxpayers, and special VAT invoices are obtained at the time of purchase, with input tax 17% and output tax 17%.