How is contribution margin different from gross margin?

Gross margin subtracts cost of goods sold, which can include fixed production overhead. Contribution margin subtracts only variable costs — including selling costs like commissions — so it's the better number for pricing and volume decisions.

What's a good contribution margin?

High enough to cover fixed costs at a volume you can realistically sell. A 20% margin needs five times the sales of a 100% margin to cover the same fixed costs.

Should I drop a product with a low margin?

Only if its contribution is negative or you can use the capacity for something better. A low-margin product with positive contribution still helps pay the fixed costs.

Business & Pricing

Contribution Margin Calculator

What each sale really leaves you after its own costs, laid out as a contribution income statement — and which lever moves profit most: price, volume, or cost.

Ben / Reviewed Sep 27, 2026 / v2.0.0

Results

Showing the numbers you calculated

Contribution per unit: $47.00; 47.00% of the price
Total contribution: $235,000.00
Operating income: $85,000.00
Break-even units: 3,192; $319,148.94 of sales
Units for your target: 5,320; $531,914.89 of sales

Contribution income statement

Contribution income statement
	Total	Per unit	% of sales
Sales	$500,000.00	$100.00	100.00%
Materials	($150,000.00)	($30.00)	-30.00%
Direct labor	($75,000.00)	($15.00)	-15.00%
Commissions and fees	($25,000.00)	($5.00)	-5.00%
Other variable costs	($15,000.00)	($3.00)	-3.00%
Contribution margin	$235,000.00	$47.00	47.00%
Fixed costs	($150,000.00)	($30.00)	-30.00%
Operating income	$85,000.00	$17.00	17.00%

What moves profit most

Operating income when one thing changes and the rest stay put.

What moves profit most
Change	Price	Units sold	Variable costs
-10%	$37,500.00	$61,500.00	$109,000.00
-5%	$61,250.00	$73,250.00	$97,000.00
As entered	$85,000.00	$85,000.00	$85,000.00
+5%	$108,750.00	$96,750.00	$73,000.00
+10%	$132,500.00	$108,500.00	$61,000.00

What this does

Contribution margin is what's left of each sale after the costs that come with it — materials, labor, commissions, fees. That leftover is what pays the rent and, eventually, you.

This lays it out as a contribution income statement, finds break-even and a profit target, and shows which lever matters most: raising prices, selling more, or cutting costs.

How the math works

contribution per unit = price − variable costs per unit
contribution ratio = contribution ÷ price
operating income = contribution × units − fixed costs

The sensitivity grid nudges one thing at a time by 5% and 10% and recomputes operating income. Price usually wins, because every extra dollar of price drops straight to profit (minus commissions).

break-even units = fixed costs ÷ contribution per unit
units for a target = (fixed costs + target) ÷ contribution per unit

A contribution income statement sorts costs by how they behave (variable vs. fixed), not by what they are — so it answers "what happens if we sell more?" much better than a regular P&L.

Check my math: a worked example

5,000 units at $100.00, with $48.00 of per-unit costs, 5% commissions and fees, and $150,000 of fixed costs.

Variable cost per unit: $53.00 (including $5.00 of commissions and fees).
Contribution: $100.00 − $53.00 = $47.00 a unit, or 47.00% of the price.
Total contribution $235,000.00 − fixed costs $150,000.00 = $85,000.00 of operating income.
A 10% price increase takes that to $132,500.00; 10% more units, $108,500.00. The biggest lever here is price.
Break-even: 3,192 units. For $100,000 of profit: 5,320 units.

These numbers come straight from the calculator using its example inputs — if the math ever changes, this example changes with it.

Mistakes I see a lot

Calling salaried staff a variable cost. If you'd pay them either way, they're fixed.
Forgetting the percentage costs — card fees and marketplace cuts come off every sale.
Chasing volume with discounts. A lower price cuts contribution on every unit, not just the new ones.
Using averages across products with very different margins. The mix matters.

Questions people ask

How is contribution margin different from gross margin?: Gross margin subtracts cost of goods sold, which can include fixed production overhead. Contribution margin subtracts only variable costs — including selling costs like commissions — so it's the better number for pricing and volume decisions.
What's a good contribution margin?: High enough to cover fixed costs at a volume you can realistically sell. A 20% margin needs five times the sales of a 100% margin to cover the same fixed costs.
Should I drop a product with a low margin?: Only if its contribution is negative or you can use the capacity for something better. A low-margin product with positive contribution still helps pay the fixed costs.

Assumptions and limits

One product (or an average unit) at a constant price and variable cost per unit; fixed costs stay fixed in the range you're looking at.
Commissions and card or platform fees are a percentage of the price, so they move when the price does. Other variable costs are per unit.
Everything made is sold — no inventory building up.
The sensitivity grid changes one thing at a time: price (commissions follow it), units sold, or the per-unit variable costs other than commissions.
Break-even and target units are rounded up to whole units.

Ben’s notes on this

Related calculators

Break-Even Point
How many units you have to sell before you stop losing money — plus your margin of safety, what it takes to hit a profit goal, and profit at different sales levels.
Markup and Margin
Markup and margin aren't the same number — and mixing them up is how prices end up too low. Check a price, or find the price for the markup or margin you want, and see what a discount really costs you.
Project Profitability
Is this job actually making money? Budget vs. actual by cost category, a forecast at completion, over- and under-billing, and what it would take to hit your target margin.
Hourly Billing Rate
The hourly rate you need to charge to pay yourself, cover your expenses, and make a profit — once you account for the hours you can't bill and the invoices that don't get paid in full.

Spot an error?

This is a public notebook and I do make mistakes. If a number looks off, tell me — I fix things and note the change in the changelog.

Disclaimer: Educational and planning use only. Results depend on what you enter and may not match your lender, your tax return, or professional accounting treatment. Informational content + opinions only — not tax/legal advice.

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