Contribution Margin Calculator

This calculator derives per-unit and whole-period contribution margin figures from total revenue, units sold, and costs. Price per unit and variable cost per unit are both revenue and variable costs divided by units sold (line 13-14), so CM Per Unit reduces to (revenue - variableCosts) / unitsSold (line 15); Total Contribution Margin is simply revenue minus variable costs, with no dependence on units sold at all (line 16). Revenue has the largest effect on nearly every output here: it's a direct term in CM Per Unit, Total Contribution Margin, and Operating Income (each equal to revenue minus some cost), it appears in both the numerator and denominator of CM Ratio and Margin of Safety, and it drives Break-Even Units and Break-Even Revenue indirectly through CM Per Unit and price per unit -- more paths into these outputs than variable costs or units sold have.

Fixed Costs never moves CM Per Unit, Total Contribution Margin, or CM Ratio -- those three describe the margin on sales alone, before fixed costs are subtracted -- and only enters Operating Income, Break-Even Units, Break-Even Revenue, and Margin of Safety, all of which represent what happens once fixed costs are covered. Break-Even Units is fixed costs divided by CM Per Unit, rounded up to a whole unit (line 19), and Margin of Safety expresses how far current revenue sits above that break-even point, as a percentage (line 21). This model assumes a single product line at a uniform price and variable cost per unit; it doesn't account for a sales mix across multiple products with different margins.