Weighted Average Contribution Margin Calculator

About this calculator

Contribution margin — sale price minus variable cost, per unit — tells you how much each unit sold contributes toward covering fixed costs and profit. When a business sells more than one product, a single overall contribution margin only makes sense as a weighted average: each product’s unit contribution margin is weighted by how many units of it are actually sold, summed, and divided by total units across all products.

This weighted figure matters because a product with a high contribution margin but low sales volume can pull the blended average less than a lower-margin product that sells in bulk — which is exactly the kind of thing a simple unweighted average would get wrong. Finance and operations teams use the weighted average contribution margin to run accurate break-even analysis and profitability forecasts across a multi-product line. This calculator takes each product’s unit contribution margin and unit volume to compute the weighted average across them.