Contribution Margin vs Break-Even: Why Fixed Costs Must Stay Out of Unit Math

Data analyst Michael Nocito published an explainer on August 11, 2026, addressing two widely misunderstood financial concepts: contribution margin and break-even analysis. The core argument is that fixed costs, such as factory rent, should never be allocated inside a per-unit calculation, as doing so dramatically distorts the break-even result. Contribution margin is defined as selling price minus variable costs only, where variable costs are those that rise with each additional unit sold. Dividing total fixed costs by the contribution margin then yields the true break-even unit count. Nocito illustrates the error with a worked example showing how misplacing fixed costs can inflate a break-even answer from roughly 750 units to 12,000 units.