Gross Margin vs Net Margin: Which One Is Telling You Something

Two margin numbers, frequently confused, answering different questions.

Gross margin asks whether your model works. For every pound of revenue, how much is left after delivering it?

Net margin asks whether your business works. After absolutely everything, how much do you keep?

The distinction matters because they move for different reasons, and mixing them up means solving the wrong problem.

The calculations

Revenue                      £120,000
− Direct costs                £48,000
= Gross profit                £72,000     Gross margin = 60%

− Operating expenses          £54,000
− Interest, tax               £4,500
= Net profit                  £13,500     Net margin = 11.25%

Direct costs scale with what you sold: materials, subcontractors, delivery labour, payment processing, per-unit fees.

Operating expenses happen regardless: rent, salaries not tied to delivery, software, insurance, marketing.

Getting that split right is most of the work, and it's where most small business accounts are wrong in the same direction — see the note on your own time below.

Gross margin diagnoses faster

The practical reason to watch it: gross margin moves for a short list of reasons.

If it falls, it's one of four things:

1. Prices fell — discounting, or a rate held while costs rose
2. Delivery costs rose — suppliers, subcontractors, materials
3. Mix shifted toward lower-margin work
4. Delivery got less efficient — more hours per job, or rework

That's a short enough list to work through in an afternoon.

Net margin, by contrast, can move because of any of those plus a dozen overhead items, interest, or a one-off. A falling net margin tells you something is wrong; a falling gross margin tells you roughly where.

Put your own time in the right place

The single most common error in small business accounts, and it flatters the numbers.

If you're delivering client work, the portion of your time spent on delivery is a direct cost. It scales with revenue. Time spent selling and running the business is overhead.

Most owners put all of their own cost in overhead, or leave it out entirely. Both make gross margin look better than it is and hide whether delivery is genuinely profitable at your current prices.

The corrected version frequently changes the answer:

| | As usually recorded | With owner delivery time | |---|---:|---:| | Revenue | £120,000 | £120,000 | | Direct costs | £48,000 | £78,000 | | Gross margin | 60% | 35% |

The second column is the real one, and it's the one that tells you whether you can afford to hire someone to do that delivery.

Blended averages hide the problem

A single company-wide margin is where losses go to hide.

Calculate it per service line and per client segment:

| | Revenue | Direct cost | Gross margin | |---|---:|---:|---:| | Retainer clients | £62,000 | £21,000 | 66% | | Project work | £44,000 | £19,000 | 57% | | Small one-offs | £14,000 | £11,000 | 21% | | Blended | £120,000 | £51,000 | 58% |

The blended 58% looks fine. The small one-off work is barely covering its own delivery, and it's probably consuming disproportionate admin and management attention on top — which doesn't even appear in that 21%.

That's a decision, and it's invisible until you split it. The answer is usually to reprice it, productise it, or stop taking it.

Percentages, over time

Amounts grow when the business grows, which conceals deterioration.

                  2024      2025      2026
Revenue          £84k      £102k     £120k     ← looks great
Gross margin      64%       61%       58%      ← getting worse every year
Net margin        16%       14%       11%

That business grew 43% and got steadily worse at what it does. Watching revenue alone, you'd celebrate. Watching margin percentage, you'd have caught it in 2025.

Track both margins as percentages, monthly, and compare year on year rather than month to month — that removes seasonality and shows the actual trend.

Which to fix, and how

Gross margin first, almost always. Fewer causes, faster fixes, and every point gained flows straight through to net.

The levers, in order of speed:

• Price. The fastest. Every extra pound is contribution with no additional delivery cost. Check your close rate first — above roughly 70% and you're priced below the market.
• Mix. Decline or reprice the lowest-margin segment. Free, and it usually creates capacity as well.
• Delivery efficiency. Documented process, less rework. Slower but compounds.
• Supplier costs. Renegotiate, or consolidate volume.

Overhead reduction improves net margin but is bounded — there's a floor below which the business can't operate. Margin improvement isn't bounded in the same way, and it compounds with volume.

Where this stops and an accountant starts

How costs are classified in your accounts, what belongs where under the accounting standards that apply to you, and how any of this interacts with tax are technical and jurisdiction- specific.

Those go to an accountant. What you should own is knowing your margin by segment, noticing when it moves, and understanding which of the four causes it was.

The mistakes

1. Watching revenue only. It grows while the business gets worse.
2. Owner delivery time in overhead. Flatters gross margin, hides the real position.
3. One blended number. A losing segment disappears into the average.
4. Amounts rather than percentages. Growth conceals deterioration.
5. Attacking overhead first. Bounded, and it's usually not where the problem is.
6. Comparing to an industry benchmark. Your own trend is the useful comparison.

What to do next

Split last year's revenue and direct costs by service line or client type, and calculate gross margin for each. The lowest one is usually well below what you assumed — and deciding what to do about it is normally worth more than any amount of cost cutting.