THE HELP GWENT ASSOCIATION

The Help Gwent Association

The Help Gwent Association

An evaluation of the techniques

Marginal

Marginal costing is a costing system under which those costs of production that vary with output are treated as product costs. This would usually include direct materials, direct labor and variable portion of manufacturing overhead. Fixed manufacturing cost is not treated as a product costs under variable costing. (Lamminmaki, 2008, pp. 163-181) Rather, fixed manufacturing cost is treated as a period cost and, like selling and administrative expenses, it is charged off in its entirety against revenue each period. Consequently the cost of a unit of product in inventory or cost of goods sold under this method does not contain any fixed overhead cost. Variable costing is some time referred to as direct costing or marginal costing. To complete this summary comparison of absorption and variable costing, we need to consider briefly the handling of selling and administrative expenses. These expenses are never treated as product costs, regardless of the costing method in use. Thus under either absorption or variable costing, both variable and fixed selling and administrative expenses are always treated as period costs and deducted from revenues as incurred.

The term 'contribution' mentioned in the formal definition is the term given to the difference between Sales and Marginal cost. Thus:

Marginal Cost = Variable Cost Direct Labour + Direct Material + Direct Expense + Variable Overheads

The term marginal cost sometimes refers to the marginal cost per unit and sometimes to the total marginal costs of a department or batch or operation. The meaning is usually clear from the context. (Ouibrahim, 2008, pp. 136)

The theory of marginal costing may, therefore, by understood in the following two steps:

1. If the volume of output increases, the cost per unit in normal circumstances reduces. Conversely, if an output reduces, the cost per unit increases. If a factory produces 1000 units at a total cost of $3,000 and if by increasing the output by one unit the cost goes up to $3,002, the marginal cost of additional output will be $.2.

2. If an increase in output is more than one, the total increase in cost divided by the total increase in output will give the average marginal cost per unit. If, for example, the output is increased to 1020 units from 1000 units and the total cost to produce these units is $1,045, the average marginal cost per unit is $2.25. It can be described as follows:

The ascertainment of marginal cost is based on the classification and segregation of cost into fixed and variable cost. In order to understand the marginal costing technique, it is essential to understand the meaning of marginal cost.

Marginal cost means the cost of the marginal or last unit produced. It is also defined as the cost of one more or one less unit produced besides existing level of production. In this connection, a unit may mean a single commodity, a dozen, a gross or any other measure of ...