Why this calculator uses gross profit, not multipliers
The standard event ROI formula is (Revenue − Cost) ÷ Cost × 100. It's the one B&W shows on its corporate event ROI calculator, which adds illustrative return multipliers for quick direction. Finance teams will ask two questions that a multiplier can't answer: where does the revenue come from, and how much of it do we keep?
So this tool takes no multipliers. You enter leads, qualification rate, win rate, deal value and gross margin, and it calculates ROI on the gross profit the business actually keeps. Every driver is your input, labelled "example default" until you change it. The revenue-based figure is still shown in the business case for reference.
| Objective | Return measured as | Break-even shown as |
|---|
| Pipeline & sales | Expected deals × deal value × gross margin | Deals needed, and win rate needed |
| Internal & retention | Leavers avoided × your replacement cost | Leavers you must retain |
| Brand & activation | Impressions × your CPM (media value, not profit) | Impressions needed |
What goes in the one-page business case
The PDF is built for a finance reviewer: itemised costs with contingency and VAT treatment, cost per registered guest and per attendee, every assumption marked as an input, the projected return with the formula written out, break-even, a 5×5 sensitivity grid (win rate and deal value from −50% to +50%), the benchmark check and a sign-off block. Contingency defaults to 10%, the standard planning figure on our budget calculator. Raise it to 12–15% for complex or first-time events.
The sensitivity grid is the part finance reads first. If ROI only stays positive when every assumption goes your way, you'll know before they tell you.
Cost per attendee and the benchmark check
Show-up rate matters. Spend R300,000 on 180 registrations and 80% attendance and you're paying for 144 people, not 180. The tool shows both figures, then compares the comparable spend per attendee (venue, catering, AV, décor, entertainment and contingency, excluding VAT, travel, internal staff time and marketing) with the published ranges in our Event Budget Calculator: R850–1,500 per delegate per day for conferences and R1,200–4,000 per guest for galas.
Building the budget first? Start with the corporate event budget template and the Johannesburg conference cost guide, then capture the scope in the Event Brief Builder. Outdoor or load-shedding risk? Add the generator line from the generator sizing calculator.
Frequently asked questions
How do you calculate event ROI?
The standard formula is (Revenue − Cost) ÷ Cost × 100. This calculator uses gross profit instead of revenue, (Gross profit − Cost) ÷ Cost × 100, because the business only keeps the margin on each deal. Both figures appear in the business case.
Where do the conversion numbers come from?
From you. Leads, qualification rate, win rate, deal value and margin should come from your CRM or past events. The pre-filled values are example defaults, not benchmarks, and the tool applies no industry multipliers.
Should I include VAT in event costs?
If your company is VAT-registered and can claim input tax, compare costs excluding VAT. Tick the VAT box only if the VAT is a real cost to you. South Africa's standard VAT rate is 15%.
Why include internal staff time?
Because it's a real cost. Forty hours of a team's time at R450 an hour is R18,000 that never appears on a supplier invoice. Finance will ask.
What if the ROI is negative?
Then say so, and use the break-even and sensitivity table to show what would need to be true. Many internal events are justified on retention or culture; the retention mode lets you model that with your HR team's figures.
How is this different from B&W's ROI calculator?
B&W's calculator gives a quick directional view using illustrative return multipliers by event type. This one builds a finance-ready case from your own inputs only, with break-even and sensitivity.
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This calculator projects outcomes from the numbers you enter. It applies no industry “return multiples”. Benchmarks are published planning ranges, not quotes. Attribution of revenue or retention to a single event is uncertain; present results to finance as scenarios. Not financial or tax advice.
