The event gross margin calculation that survives a first look from group finance

A show director sends a one page summary to the group CFO with a margin of 63 per cent on it. Twenty minutes later the reply comes back asking why the same show is at 33 per cent in the divisional pack.

Nobody has done anything wrong. Both figures are arithmetically correct and they measure different things, and the event gross margin calculation only becomes useful once the page says which of the two it is showing.

What the calculation needs before it means anything

Gross margin is revenue less direct cost, divided by revenue. The whole difficulty sits in the phrase direct cost, and an event business has more room for argument there than most.

The workable definition is the cost that disappears if the show does not happen. That is also the definition a listed organiser has to defend in a filing. Emerald Holding's Form 10-Q for the quarter ended 30 June 2025 states plainly that direct trade show costs are recorded in cost of revenues and all other costs are recorded in selling, general and administrative expenses. Above the line sits floor build through general service contractors, venue costs, sponsorship costs owed to endorsing trade associations, and other event related expenses covering temporary labour for security, shuttle buses, speaker fees, food and beverage, and event cancellation insurance. Below it sit the sales and marketing salaries, the planning team and the corporate recharge.

Write that boundary down in one sentence at the top of the pack. Any margin quoted without it is a number waiting to be contradicted by a colleague using a different one.

Working it on a set of filed accounts

Take the same filing, because the figures are public and anyone can check them.

For the six months ended 30 June 2025, Emerald Holding reported revenues of 253.2 million dollars and cost of revenues of 92.0 million. Revenue less direct cost is 161.2 million, and 161.2 divided by 253.2 is 63.7 per cent. That is the gross margin.

Keep going down the same statement. Selling, general and administrative expense was 101.2 million and depreciation and amortisation was 14.0 million, which leaves operating income of 46.0 million. Divide that by 253.2 and the operating margin is 18.2 per cent.

So the same six months produced 63.7 per cent and 18.2 per cent. The gap of 45.5 percentage points is entirely the cost of running the company that sells the shows. For the comparable half of 2024 the same arithmetic gives 219.4 less 80.6, which is 138.8, or 63.3 per cent gross, and operating income of 30.7 million on 219.4, which is 14.0 per cent. Gross margin moved four tenths of a point across the year while operating margin moved 4.2 points, which tells you where the year was actually won.

Why do two true margins differ by thirty points?

Bring it down to one show, where the effect is sharper because the overhead is allocated rather than incurred.

A show bills 6.9 million of revenue and carries 2.4 million of direct cost. Gross margin is 4.5 million on 6.9 million, which is 65.2 per cent. Now charge the show with the sales and marketing that produced it, 1.35 million, and its share of the divisional overhead, 840,000. The show contributes 2.31 million, which is 33.5 per cent of revenue.

Both numbers describe the same show. The first says what the show earns before anyone tries to sell it. The second says what the group keeps. A show director quoting 65 and a finance director quoting 33 are having a real disagreement only if neither has said which line they stopped at.

My preference is to publish both on the same page with the bridge between them shown as two named subtractions, because a reader who can see 65.2 becoming 47.6 after sales and marketing and then 33.5 after overhead learns something. A reader who sees one percentage learns nothing and remembers it wrongly. How central overhead gets allocated to a show at all is an argument of its own, and it should not be settled inside a margin slide.

What group finance will ask first

Three questions come back reliably, and the pack is better if it answers them before they are asked.

Where is the sales commission. Commission on space sold is a direct cost of the sale and it disappears if the sale does not happen, so there is a decent argument for it above the line. Most groups put it below, in selling expense, which makes gross margin higher and comparable to the peer group. Pick one and never move it mid year.

What happened to the deferred revenue. A show that slipped into the next period takes its revenue with it and often leaves committed cost behind, which mangles a margin computed on a calendar period. Margin should be computed per edition wherever the systems allow it, and only rolled to a period afterwards.

Is the direct cost complete. Late invoices from a general service contractor arriving six weeks after the show are the standard reason a margin quoted on the Monday after close is two or three points too good. If the pack is produced before the cost is closed, say so on the page and give the accrual assumption.

Rebuilding the calculation when the ledger fights you

Most of the work in an event gross margin calculation is mapping, and it is duller than it sounds and more consequential than the arithmetic.

The general ledger was built for statutory reporting, so it groups cost by nature: travel, professional fees, temporary labour, rent. Gross margin needs cost grouped by whether it follows the show. Those two groupings cut across each other. Temporary labour includes both the security guards on the aisles, which is direct, and the agency contractor covering a maternity leave in the marketing team, which is not. Rent includes both hall hire and the office.

The fix is a single mapping table with one row per account code and one column holding the value direct or indirect, owned by one named person and versioned. Not a rule applied in a spreadsheet each quarter by whoever built that quarter's pack. When the mapping lives in the pack, the margin changes every time the analyst changes, and the year on year series stops meaning anything.

Two tests will tell you whether your mapping is sound. Re-run last year's margin using this year's mapping and see how far it moves. A shift of more than half a point means the mapping changed and your published series is not comparable to itself. Then take the ten largest cost rows on the show and ask, for each, whether it would have been spent if the show had been cancelled twelve months out. If two of the ten give an uncomfortable answer, those two are the whole argument, and settling them is worth more than any amount of further refinement. This mapping is also what makes the full profit and loss reproducible rather than reconstructed each time.

Does the margin figure travel between shows?

Only within a portfolio using one rule, and even then with care.

Two shows in the same portfolio can differ by fifteen points of gross margin for reasons that have nothing to do with how well they are run. A show where the organiser resells stand build carries that cost above the line and reports lower margin on higher revenue. A show where exhibitors contract directly with the general service contractor never sees that revenue or that cost at all. The second show looks better on margin and may be worth less in absolute terms.

Absolute contribution is the figure to rank shows on. Margin is the figure to track a single show against its own history. Using margin to rank shows against each other rewards the ones with the least pass through revenue, which is an accident of how the contracts were written.

For an outside comparison, UFI's Global Exhibition Barometer in its 36th edition, published in January 2026 from a survey of 378 companies across 57 countries, found 31 per cent of companies reporting an annual increase in operating profit of more than 10 per cent for 2025 and 57 per cent declaring a stable result within plus or minus 10 per cent. That is a direction of travel across the industry, and it says nothing about the level any individual show should reach.

Where this stops

Gross margin is a ratio, and ratios hide the two things that usually matter most in an event business.

The first is scale. A show can improve margin by two points and lose 400,000 of contribution, because it shrank. The margin went up because the fixed element of direct cost fell with the floor while the achieved rate held. Nobody celebrating the margin noticed the show got smaller. Always publish absolute contribution next to the percentage, and check both moved the same way.

The second is that a period margin for an event business is partly a calendar artefact. Revenue lands when the show is staged, and a half with four shows in it looks structurally different from a half with two, regardless of performance. Comparing gross margin between halves without knowing the event calendar produces confident nonsense. That is a whole subject on its own and this post leaves it there.

Take your last closed edition, write the direct cost boundary in one sentence at the top of a blank sheet, and rebuild the margin underneath it as three lines: revenue, direct cost, gross margin, then the two subtractions that take you to contribution. If the resulting gross margin differs by more than a point from the one currently in the pack, the difference is a definition problem worth fixing before the next board meeting. The cost side of that boundary and the hall level view underneath it are both part of the same event finance picture.