The office Christmas party has a failure mode all of its own: it is planned by someone with a budget and a spreadsheet, attended by people who did not choose to be there, and judged entirely on whether the drinks ran out. Here are the numbers that stop that happening.
Start with realistic attendance
Do not plan for headcount. Plan for 70–85% of those who RSVP yes — office party drop-off is reliably high, and it climbs the closer the date sits to Christmas itself. Over-catering by 15% costs money; under-catering by 15% is the thing people remember.
Drinks per head
The standard formula applies — guests × (hours + 1) — but office parties have a distinct shape. The first ninety minutes are heavy, because people arrive at the same time straight from work and drink faster while the room warms up socially.
| Attending | Hours | Total drinks | Rough split |
|---|---|---|---|
| 25 | 4 | 125 | 10 wine · 30 beer · 6 spirits · 25 soft |
| 50 | 4 | 250 | 20 wine · 60 beer · 12 spirits · 50 soft |
| 100 | 4 | 500 | 40 wine · 125 beer · 25 spirits · 100 soft |
| 150 | 5 | 900 | 72 wine · 225 beer · 45 spirits · 180 soft |
Wine counts are bottles (five glasses each); beer counts are bottles or cans; spirits are bottles at a 1.5 oz pour.
The dry share is much bigger at work
This is the number office planners get most wrong. At a work event a materially larger proportion of the room is not drinking — people who are driving, who do not drink at all, who are pacing themselves in front of colleagues, or who simply do not want to be visibly drunk at a work function.
Plan one non-alcoholic serving per guest per hour, for every guest, on top of the alcohol. Not as a share carved out of it. A 100-person, 4-hour party needs 400 non-alcoholic servings available. In practice you will use fewer, but running out of anything decent to drink at a work party leaves non-drinkers stood by a tap, and people notice.
Make at least one option feel like a real drink — an alcohol-free beer, a proper soft cocktail, sparkling in a wine glass. See the non-alcoholic guide.
Food per person
If canapés replace dinner — which at an evening office party they usually do, whatever the invitation says — plan 10–14 pieces per person. If a meal is served, 4–6 pieces beforehand is right.
Feeding people properly also directly reduces your alcohol problem. A room that has eaten drinks more slowly and behaves better. The appetizer guide has the per-hour tables.
Timing the bar
- A drinks token or tab limit is the standard control, and 3–4 drinks per person is the usual allocation. Expect a bar rush in the final twenty minutes if you announce the tab is closing — announce it thirty minutes ahead to spread it.
- Serve food early, within the first hour. Late food arrives after the damage.
- Water on every table, not just at the bar. Availability drives consumption far more than intent.
- Close the bar before the venue closes. Half an hour of coffee and water at the end changes how the evening finishes.
The duty of care bit
An employer-organised party carries real responsibility. Arrange transport or share taxi details in advance, brief someone to stay sober and keep an eye on the room, and never make drinking feel compulsory. These are not just legal considerations — they are the difference between a party people enjoyed and one HR spends January dealing with.
Size your own event with the party drink calculator.