Contribution Margin Calculator

About this calculator

The contribution margin is what's left from a sale after covering variable costs, calculated per unit as selling price minus variable cost per unit, or as a ratio (contribution margin ÷ selling price) to express it as a percentage. It's called "contribution" because that amount contributes toward covering fixed costs first, and toward profit once fixed costs are covered — it deliberately excludes fixed costs, unlike gross margin which is based on total cost of goods sold.

Managerial accountants and business owners use contribution margin as the core input for break-even analysis (fixed costs ÷ contribution margin per unit = break-even units) and cost-volume-profit (CVP) analysis, and to decide which products or product lines are most worth prioritizing when capacity is limited. A high contribution margin ratio means each additional sale adds more toward covering fixed costs and generating profit, making it a key metric for pricing decisions and product mix optimization.