Variable costVariable costs are costs that change as the quantity of the good or service that a business produces changes. Variable costs are the sum of marginal costs over all units produced. They can also be considered normal costs. Fixed costs and variable costs make up the two components of total cost. Direct costs are costs that can easily be associated with a particular cost object. However, not all variable costs are direct costs. For example, variable manufacturing overhead costs are variable costs that are indirect costs, not direct costs.
Contribution marginContribution margin (CM), or dollar contribution per unit, is the selling price per unit minus the variable cost per unit. "Contribution" represents the portion of sales revenue that is not consumed by variable costs and so contributes to the coverage of fixed costs. This concept is one of the key building blocks of break-even analysis. In cost-volume-profit analysis, a form of management accounting, contribution margin—the marginal profit per unit sale—is a useful quantity in carrying out various calculations, and can be used as a measure of operating leverage.
Fixed costIn accounting and economics, 'fixed costs', also known as indirect costs or overhead costs, are business expenses that are not dependent on the level of goods or services produced by the business. They tend to be recurring, such as interest or rents being paid per month. These costs also tend to be capital costs. This is in contrast to variable costs, which are volume-related (and are paid per quantity produced) and unknown at the beginning of the accounting year. Fixed costs have an effect on the nature of certain variable costs.
Marginal costIn economics, the marginal cost is the change in the total cost that arises when the quantity produced is incremented, the cost of producing additional quantity. In some contexts, it refers to an increment of one unit of output, and in others it refers to the rate of change of total cost as output is increased by an infinitesimal amount. As Figure 1 shows, the marginal cost is measured in dollars per unit, whereas total cost is in dollars, and the marginal cost is the slope of the total cost, the rate at which it increases with output.