Gross margin, contribution margin and net margin subtract different sets of costs from revenue. Contribution subtracts variable costs and does not always sit between the other two measures. State the cost boundary and decision horizon. Net margin describes company net income; a configured project margin is a different management measure.
Terms used in this guide. fee: the amount charged to the client; cost: the expense included in the stated project model; margin: revenue left after the included costs; margin percentage = that amount / revenue × 100; baseline: the approved original plan kept for comparison.
In plain words
Gross margin is the fee minus the cost of delivering the work. Contribution margin is a different cut: it takes off the costs that rise with the deal, such as sales commission (the exact list depends on the firm’s policy). Net margin is for the whole firm: it takes off everything, including all overhead, financing and tax. At deal level the nearest view is the margin after allocated overhead. In a simple case the three step down in that order, though they do not always. Each answers a different question, and contribution margin is the one that matters when you are deciding how much discount you can give.
Who this helps: Sales managers and account executives who negotiate price, and the finance staff who explain margins to them.
Questions this guide answers:
- What is the difference between contribution margin and net margin?
- What is gross margin versus net margin?
- What is net contribution margin?
- Which margin should sales use when giving a discount?
Gross margin vs contribution margin vs net margin: what is the difference?
Gross margin subtracts the cost of sales or service delivery under the firm’s accounting policy. Contribution margin subtracts variable costs for the decision being analyzed. Net margin is net income divided by revenue after the firm’s relevant operating expenses, financing costs and tax. Operating margin is a different measure, before financing and tax.
Gross margin % = (revenue − cost of sales) / revenue × 100
Contribution margin % = (revenue − variable costs) / revenue × 100
Net margin % = net income / revenue × 100
Contribution need not sit between gross and net margin. Salaried delivery labor may be fixed over a short decision horizon but included in cost of sales; sales commission may be variable but excluded from cost of sales. Define the time horizon and cost behavior before comparing the measures.
A positive incremental contribution can help cover fixed costs, but it does not alone justify a price. Consider capacity, opportunity cost, contractual exposure and the firm’s margin policy. Project costs allocated for management reporting require reconciliation before they explain company net income.
How does a 10% discount cut a quarter of your margin?
Contribution margin is what makes a discount's real cost visible, and the arithmetic surprises most people the first time they run it. Take a deal priced at USD 100,000 with a 40% contribution margin: variable delivery cost is USD 60,000, so contribution margin is USD 40,000.
| Measure | Before discount | After a 10% price cut |
|---|---|---|
| Price | USD 100,000 | USD 90,000 |
| Variable delivery cost | USD 60,000 | USD 60,000 |
| Contribution margin (dollars) | USD 40,000 | USD 30,000 |
| Contribution margin (%) | 40.0% | 33.3% |
In this example the included cost stays fixed at USD 60,000 while fee falls from USD 100,000 to USD 90,000. The USD 10,000 concession consumes 25% of the original USD 40,000 contribution. If commission or another cost changes with revenue, recalculate that cost: not every dollar of discount then reduces contribution by a full dollar.
Margin erosion % = Discount % / Contribution margin %
Margin erosion % = 10% / 40% = 25%
That single ratio is the mental model worth carrying into a negotiation: the lower a deal's starting contribution margin, the more damage the same percentage discount does. The full worked comparison across different starting margins, plus how much extra volume would be needed to recover a discount, is covered in how discounts affect project margin.
Which margin should you use for which decision?
| Metric | Question it answers | What it cannot tell you alone |
|---|---|---|
| Gross margin | Did delivery cost roughly what we expected relative to the fee? | Whether a live price change still leaves the deal worth taking. |
| Contribution margin | Does this specific deal, at this specific price, still add more than it costs to deliver? | Whether the whole business is profitable after fixed overhead. |
| Net / operating margin | Is the business, across all deals this period, actually profitable? | What any single deal should be priced or discounted to. |
For a price concession, consider the incremental contribution alongside capacity, risk and the firm’s full-project margin policy. During delivery, compare the relevant margin layers with the approved baseline. Finance reconciles those project views to company operating and net profit; no single engagement can explain the entire company result.
How do you use contribution margin at the negotiating table?
- Before the call, know the deal's contribution margin, not just its gross-margin target. Back out variable delivery cost from the quoted price.
- When a discount lands, apply the erosion formula immediately: discount % divided by contribution margin %.
- Treat contribution margin as the floor. A price that drives it to zero means every additional hour of delivery loses money. Do not cross that line without an escalated decision.
- Track cumulative discounting, not just the latest ask. A second 10% cut applies to an already-shrunk margin, so its erosion is larger than the first cut's.
- Hand off cleanly. Delivery and finance later track the same margin layers against the approved pricing baseline, so agree which layer the target refers to before the deal is won.
Where does Managed Margin fit in?
Managed Margin reports configured project layers: gross delivery margin subtracts labor and direct categories; contribution also subtracts configured variable categories; Managed Margin subtracts the remaining modeled overhead. Because delivery labor may be fixed in a short-run accounting analysis, the product’s layer called contribution is not automatically the textbook revenue-minus-variable-cost measure. Inspect Cost & Margin Rules before comparing the figures.
Which costs sit in each layer is set once in Cost & Margin Rules, so sales, pre-sales and finance read the same definitions. Net margin is not calculated: it needs company-wide costs such as depreciation, interest and tax, which are not recorded at project level.
Discounts are not a separate entry: the quoted price is the price after any discount, so test a discount as its own pricing strategy and compare the margins. Managed Margin does not calculate net or operating margin and does not replace the finance system of record.
What should you check before negotiating a price?
- Know the deal's contribution margin before the call, not just its gross-margin target.
- Define which costs are genuinely variable for this deal versus fixed regardless of outcome.
- Run the erosion formula on any requested discount before responding.
- Treat zero contribution margin as a hard floor requiring escalation.
- Track cumulative discounts against the already-reduced margin, not the original one.
- State which margin layer every target and report uses, so negotiation figures and delivery figures stay comparable.
- Never promise a net-margin or company-profitability outcome from a single deal.
For the base project-margin calculation, see how to calculate project margin. For pricing mechanics, read project pricing for professional services and cost rate vs billing rate. Before quoting a range at all, see giving a ROM estimate without anchoring.
- Project Margin Rollups: Formula & Example
- Profit vs Cash Flow on a Project: How Payment Terms Matter
- How to Share Project Margin With Sales Without Showing Salaries
Real example: a sales manager is asked for 10% off
An illustrative story with invented figures, to show how the idea works in a real office.
Sam, a sales manager, has a deal at USD 100,000. Delivery costs USD 62,000, so gross margin is 38%. Commission is 5%, or USD 5,000, so contribution is 100,000 minus 62,000 minus 5,000, which is USD 33,000 (33%). The firm then charges the deal USD 12,000 as its share of overhead, which leaves USD 21,000 (21%). That is the margin after allocated overhead, a management view of the deal, not the firm’s net profit.
The client asks for 10% off. The fee drops to USD 90,000 and commission to USD 4,500, but delivery still costs USD 62,000. Contribution becomes USD 23,500, which is 26%. Sam sees that a 10% price cut removed almost 30% of the money the deal contributes.
He offers a smaller discount tied to a longer contract instead. He could only decide that because he looked at contribution, not just gross margin.
When do you use each margin, and what comes before and after?
| Person | Decision | Margin to use |
|---|---|---|
| Sales manager | A client asks for a discount | Contribution margin of this deal |
| Project manager | Is delivery going as planned? | Gross (delivery) margin against the baseline |
| Finance | Is the business profitable? | Net or operating margin across all deals |
| Leadership | Is the project worth taking after the costs it manages? | Managed margin |
Gross, contribution, net or managed margin: which should you use?
Firms use several margin definitions.
| Approach | Use it when | Watch for |
|---|---|---|
| Gross margin | Comparing delivery efficiency | Ignores variable costs |
| Contribution margin (this guide) | Discount and deal decisions | Needs variable costs |
| Net margin | Firm-level view | Allocation conventions |
| Managed margin | Margin after costs the project manages | Needs a clear definition |
Use contribution margin at the table, gross margin to judge delivery and net margin for the firm. See what managed margin means for the view used in Managed Margin.
Gross, contribution and net margin: frequently asked questions
Which margin should a salesperson use?
Contribution margin for deal and discount decisions, because it includes commission and other variable costs.
Why is the 10% discount so costly?
A discount reduces fee but not cost, so it comes straight out of margin dollars. See the guide on how discounts affect project margin.
Is net margin at deal level real profit?
No. It depends on how overhead is allocated, so use it for comparison, not as firm profit.
What is the difference between contribution margin and net margin?
Contribution margin is revenue minus the variable costs of a decision, so it tells sales whether a deal at a given price still adds more than it costs. Net margin is net income divided by revenue for the whole business after all operating expenses, financing and tax, so it describes the firm, not one deal.
What is gross margin versus net margin?
Gross margin is revenue minus the cost of delivering the service, divided by revenue. Net margin is what is left after every expense, including overhead, financing and tax, divided by revenue. Gross margin judges delivery; net margin judges the whole business.
What is net contribution margin?
It is not a standard measure. People use it for contribution margin after the costs the firm attaches to a deal, such as commission, so always ask which costs are included. In this guide, contribution margin means revenue minus the costs that change with the decision; the pricing guides use margin amount for what is left after all included costs and charges.
Continue the sequence: guides to read next
- What Is Managed Margin? Meaning, Formula and Software: the margin view used in Managed Margin
- How to Calculate Project Margin (Formula + Example): the full project margin calculation
- How a Discount Affects Project Margin: Formula and Example: the discount arithmetic in contribution terms
Sources and methodology
- Corporate Finance Institute, Contribution Margin Overview. Used for the contribution-margin definition and formula.
- Corporate Finance Institute, Gross Margin Ratio. Used for the gross-margin definition and formula.
- Corporate Finance Institute, Operating Profit Margin and Net Profit Margin. Used to distinguish operating margin and net margin from gross and contribution margin.
- Managed Margin's gross-margin and Managed Margin calculations were reviewed against the current Managed Margin application on 26 September 2026. The discount and negotiation figures are original, illustrative worked examples, not customer results.