The objective was to apply direct costing (DC) methodology to calculate dairy farms costs located in the semiarid region of Sergipe, Brazil. Productive and financial data were used from 30 dairy farms, in which milk market is the farms primary activity. Costs were segregated as fixed and variable, as profitability index, contribution margin (CM) and net income (NI). Profit before interest, taxes, depreciation and amortization (EBITDA) was adopted as financial index. In rural farms analyzed, CM was negative equivalent to R$ - 0.06 per liter of milk, due to the high production cost setting the sold goods cost (COGS), exceeding the net income by 4.49 percentage points, equivalent to R$ 1.31 per liter of milk, contributing to the result of R$ -0.20 (twenty cents) per liter of milk, equivalent to -16.8% of the raw milk price. The direct costing methodology has applicability to calculate costs in dairy farming, as it provides full data and information from the economic-financial point of view, well segregated.