Two of the most important financial metrics in any business — but they measure completely different things. Here is exactly what each one tells you and how to use them together.
Gross margin and net margin are both expressed as percentages of revenue, but they measure different things at different levels of the P&L. Confusing them is one of the most common commercial mistakes UK SME owners make.
Gross margin is revenue minus the direct cost of the goods or services sold (cost of goods sold, or COGS), expressed as a percentage of revenue. It measures the profitability of the product or service itself, before overheads are considered.
What counts as COGS? Direct materials, direct labour, freight, duty on imported goods, and any cost that moves directly with sales volume. Fixed overheads — rent, admin salaries, software — do not belong in COGS.
Net margin is what remains after all costs — including overheads, fixed costs, interest, and tax — are deducted from revenue. It represents the actual profit the business keeps from every pound of revenue generated.
The difference between gross and net margin is your overhead burden as a percentage of revenue. In the example above: 40% gross margin minus 12% net margin = 28% of revenue going to overheads. The lower this gap, the more efficiently the business converts gross profit into net profit.
| Gross Margin | Net Margin | Overhead Gap | Verdict |
|---|---|---|---|
| 50% | 18% | 32% | Strong |
| 40% | 12% | 28% | Healthy |
| 35% | 5% | 30% | Tight |
| 25% | 2% | 23% | Fragile |
Distribution/wholesale: Gross 20-35%, Net 4-10%. Retail: Gross 40-60%, Net 5-15%. Professional services: Gross 60-80%, Net 15-30%. Manufacturing: Gross 30-50%, Net 8-18%. E-commerce: Gross 35-55%, Net 5-15%.
Gross margin is the one you have the most control over in the short term — through pricing, purchasing, and product mix decisions. Net margin is the outcome of both gross margin management and overhead control. A business with a healthy gross margin but poor net margin has an overhead problem. A business with a thin gross margin cannot compensate with overhead efficiency alone — the problem is structural.
The LumixAI 12-Month P&L tool calculates both margins from your actual figures and benchmarks them against your sector.
It depends on sector. For retail: 40-60%. Distribution: 20-35%. Professional services: 60-80%. Manufacturing: 30-50%. The most important benchmark is whether your gross margin is sufficient to cover overheads and generate a viable net margin.
A net margin of 5-8% represents commercial viability for most UK SMEs. 10-15% is healthy. Above 15% is strong. Below 5% leaves very little buffer against cost increases or revenue fluctuations.
The gap between gross and net margin is your overhead burden. A high gross margin with a low net margin means overheads are consuming too large a proportion of revenue. The fix is to review fixed costs, not to raise prices.
Three levers: reduce direct costs to improve gross margin, reduce fixed overheads to narrow the gross-to-net gap, or increase revenue to spread fixed overheads across a larger base. All three should be modelled before acting.
The LumixAI 12-Month P&L tool calculates gross and net margin from your figures and benchmarks against sector thresholds.
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