Coût

Coût is a fundamental economic concept referring to the value of resources used to produce or obtain goods and services. In economics and accounting, the coût of a product or project reflects both monetary outlays and the value of foregone alternatives.

Costs are categorized by time horizon and behavior. Fixed costs stay constant with output in the short run; variable costs vary with output. Total cost is the sum of fixed and variable costs; average cost is total cost divided by output; marginal cost is the cost of producing one more unit.

Key related concepts include opportunity cost, which equals the foregone benefit of the next best alternative, and sunk cost, a past expense that should not affect current decisions.

Cost measurement methods include cost accounting, standard costing, and activity-based costing. For decision making, costs are used in pricing, budgeting, and capital budgeting, including break-even analyses and present-value calculations.

In business and public policy, the notion of coût interacts with efficiency, productivity, and competitiveness, and is central to cost-benefit analysis comparing alternative courses of action.