Gross Margin Calculator

Gross margin is what remains from a sale after the direct cost of delivering it. Per unit it is simply the selling price minus the unit cost, and as a percentage it is that difference divided by the price. The percentage matters more than the absolute figure when comparing products, because it tells you how much of every unit of revenue you actually keep before overheads.

Add a row for each product, SKU, or service line. Enter the selling price per unit, the cost of goods sold per unit, and the number of units sold in the period. Unit cost should include everything that scales with each sale: materials, direct labor, packaging, inbound freight, and payment processing. Rent, salaries, and software belong in overheads, not here, because they do not vary with the next unit sold.

The calculator produces two separate rankings, and the gap between them is usually the interesting part. The first ranks by unit margin percentage, showing which products are most profitable per sale. The second ranks by total contribution, which is unit margin multiplied by volume, showing which products actually generate the most gross profit. A product can top one list and sit near the bottom of the other.

It also reports your blended gross margin across the whole mix, computed as total contribution divided by total revenue rather than as an average of the individual percentages. That distinction matters: a high volume low margin line pulls the blended figure down far more than a simple average would suggest. Finally, a concentration figure shows what share of gross profit comes from your top fifth of products, which is the fastest way to see whether the business is leaning on a handful of SKUs.

A shop sells three products. Product A sells for 100 with a unit cost of 60, and moves 100 units. Product B sells for 50 with a unit cost of 20, and moves 400 units. Product C sells for 20 with a unit cost of 18, and moves 1,000 units. Unit margins are 40, 30, and 2, giving margin percentages of 40, 60, and 10 percent. Total contributions are 4,000, 12,000, and 2,000, on revenues of 10,000, 20,000, and 20,000.

Total revenue is 50,000 and total contribution is 18,000, so the blended gross margin is 36 percent. Notice that a simple average of the three percentages would give 36.7 percent, which overstates the result: the blended figure is weighted by revenue, and Product C contributes a fifth of the sales at only ten percent margin. Product B leads both rankings here, but the two often diverge. Product C is the one to examine: it ties Product A for revenue while producing a sixth of the gross profit, so a small price rise or cost reduction on that line moves the blended margin more than the same change anywhere else.

Use it when deciding where to focus, whether that is which products to promote, which to reprice, and which to discontinue. It is also the right starting point before a pricing review, because seeing unit margin next to volume tells you which lines can absorb a price change and which cannot. Run it again after any supplier cost increase to see which products are quietly slipping toward break even.

The concentration figure is worth checking on its own before you make plans that depend on a single product. If the top fifth of your SKUs produces most of the gross profit, the business is more exposed to a supplier problem or a competitor undercutting one line than the revenue figures alone suggest. Pair this with the break even calculator to convert a target margin into the sales volume that actually covers your fixed costs.

The most common mistake is averaging the individual margin percentages instead of blending them by revenue. A simple average treats a product selling ten units the same as one selling ten thousand, which usually flatters the result. Always divide total contribution by total revenue. A related error is confusing gross margin with markup: a product costing 60 and selling for 100 has a 40 percent margin but a 67 percent markup, and quoting one when you mean the other leads to systematic underpricing.

A second mistake is putting fixed costs into unit cost. Rent, salaries, and software do not change with the next unit sold, so including them in cost of goods sold understates every margin and makes healthy products look marginal. A third is judging products by unit margin percentage alone. A high margin product selling almost nothing contributes little, while a modest margin on high volume can be the line that actually pays the bills. That is precisely why this tool shows both rankings.

This calculator measures gross margin only, meaning revenue less the direct cost of goods. It says nothing about net profitability, because rent, salaries, marketing, software, and every other overhead sit below this line. A product with a healthy gross margin can still lose money once its share of overheads is counted. The model also assumes one price and one unit cost per product across the whole period, so it does not capture discounting, promotional pricing, tiered supplier costs, returns, shrinkage, or currency movement on imported goods. It uses units sold rather than units produced, so it ignores inventory timing and unsold stock. Results are educational estimates and should not replace advice from a qualified accountant.

Gross margin tells you what each sale keeps, not how many sales you need. The break even calculator turns a contribution margin into the unit volume that covers your fixed costs, which is the natural next question once you know your margins. For a product line with a stable sales mix, the multi product breakeven calculator applies a weighted contribution margin across the whole range at once.

If you are examining pricing rather than product mix, the CVP target profit calculator works backwards from a profit goal to the price and volume combination that reaches it. For subscription businesses where the same customer buys repeatedly, gross margin per unit matters less than retention, and the LTV and CAC ratio calculator is the better fit.