Gross margin vs net margin

Both express profit as a percentage of revenue. They differ in how far down the income statement the profit is measured. Gross margin stops after the cost of revenue, the direct cost of producing the goods or services sold. Net margin goes to the bottom of the statement and subtracts everything else as well: sales and administration, research, interest, tax, and any one-off gains or losses.

The two go by several names. Gross margin is also called gross profit margin, and net margin is also called net profit margin or simply profit margin. Each pair is the same figure.

Operating margin sits between them. It subtracts operating expenses from gross profit and stops before interest and tax.

Both come from the income statement. Divide gross profit by revenue for gross margin, and net income by revenue for net margin, then multiply by 100 for a percentage.

The statement below is hypothetical, but its lines are the ones a real income statement carries, with every line also shown as a share of revenue. The margins are the shares on the three profit lines: 60% gross, 25% operating and 18% net.

Gross margin can hold steady or rise while net margin falls. The causes then sit below gross profit: more spending on sales or research, a larger interest bill after borrowing, a higher tax rate, or a writedown.

Net margin can rise while gross margin falls. Revenue growing faster than fixed overheads lifts operating and net margin even when each sale earns less, and a one-off gain such as an asset sale or a tax credit lifts net margin with no change to the business.

Reading the three margins together locates where the money goes. A strong gross margin with a weak operating margin indicates heavy spending on overhead, sales or research. Operating and net margins far apart usually indicate substantial interest, tax, or both.

They answer different questions. Gross margin is about the product: little besides pricing and production cost moves it, so it shows pricing pressure earliest and is the figure most comparable between direct competitors, once you have checked where each draws its cost of revenue line (below).

Net margin describes what is left for shareholders after everything, and it is the figure earnings per share and the price-to-earnings ratio are built on. Its weakness is noise, so it is read across several years rather than one.

The three margins describe business models more than they describe quality. A software company sells copies of something built once, so its gross margin is high and most of its costs sit below that line. A grocer buys and resells goods at a small markup and makes its money on volume and working capital.

The shapes below are illustrative rather than specific companies, but the pattern is real and it is why a filter on margin is a filter on industry. A 3% net margin is ordinary for a grocer and would be a crisis at a software company.

The comparison that carries information is against the same company over time, or against direct competitors selling the same thing through the same channels.

Gross margin is the most structural of the three. It reflects what the company can charge relative to what the product costs to make, which is close to a direct measure of competitive position, and it is the hardest to improve by cutting costs elsewhere.

It is also the most stable, so movement in it is usually substantive: input costs rising faster than prices, discounting to hold volume, or a change in what the company sells. A gross margin falling a point a year over five years is a stronger signal than a volatile net margin over the same period.

Where the cost of revenue line is drawn is a company decision, though, and it varies. Some companies put customer support and hosting above the line and some below, so a gross margin gap between two apparently similar businesses is worth checking against their accounting policies before it is read as a difference in pricing power.

Operating margin subtracts operating expenses from gross profit: selling, general and administrative costs, and research and development. The gap between gross and operating margin is therefore the cost of running the business, and operating margin is the one that tracks the business as it is run.

It is the margin most affected by scale: fixed overheads spread across growing revenue push it up without anything about the product changing, and it falls sharply when revenue drops because those costs do not fall with it. That is operating leverage, and it is why margins at cyclical companies swing more than their revenue does.

Net income sits at the bottom of the statement, so every unusual item lands in it: legal settlements, asset sales, writedowns, one-off tax items, currency movements. A single event can double or halve net margin with no change to the underlying business.

It is therefore the wrong figure on which to judge a single year, and the reason margins are read across a decade. Company pages show ten years for exactly this: the level in any one year says much less than the shape across all of them.

Banks, insurers and other financial businesses do not report a cost of revenue, because the concept does not apply. Their income statements are built around interest, fees, claims and provisions rather than the cost of producing units, so a gross margin for such a company is absent rather than low.

That matters when screening. A filter on gross margin excludes every financial company from the results, and a sort that reads a missing margin as zero places them at the bottom of a ranking they were never part of.

Comparing margins across industries, which compares business models rather than performance.

Confusing gross margin with markup. Margin divides gross profit by revenue and markup divides it by cost, so a product bought for $40 and sold for $100 has a 60% gross margin and a 150% markup.

Judging a year on net margin, which absorbs every one-off item in the accounts.

Reading a rising operating margin as improved efficiency when it is operating leverage on rising revenue, which reverses when revenue falls.

Comparing gross margins without checking what each company puts above the cost of revenue line.

Treating a margin as a substitute for a return measure. A high margin on a business that needs enormous capital to produce it is not the same as a high return on that capital.