You have booked the venue, chosen the caterer, and now you are staring at a spreadsheet trying to work out how much prosecco, beer, gin, and wine to order for 120 guests. You have Googled it three times and found three wildly different answers. One says two drinks per person per hour. Another says five. Your mum reckons Uncle Dave alone will get through a crate. Welcome to the single most stressful drinks calculation in event planning.
Getting the drinks-per-head estimate wrong is costly either way. Over-order and you are left with cases of warm lager nobody wanted. Under-order and you face the mortifying moment when the bar runs dry at half nine. After staffing thousands of events across the UK, from intimate garden parties to 500-guest weddings, we have seen every scenario. Here is what actually works in practice.
The Baseline Formula That Actually Holds Up
Forget the oversimplified one-drink-per-person-per-hour rule. It is too blunt. Real consumption follows a curve. Guests drink more in the first two hours, ease off during food, and then pick up again for the evening session. A more reliable formula for a typical UK event lasting five to six hours is:
- Arrival drinks: 1.5 drinks per guest in the first hour. People are socialising, the bar is a focal point, and they tend to grab something quickly.
- During the meal: 0.5 to 1 drink per person per hour. Wine on tables slows footfall at the bar considerably.
- Evening reception: 1 to 1.5 drinks per person per hour. This is when spirits, cocktails, and beer consumption climbs again.
For a six-hour event with 100 guests, that gives you roughly 550 to 700 drinks in total. That sounds like a lot, but remember this includes everything: welcome fizz, table wine, pints, gin and tonics, and soft drinks.
The Variables That Throw Off Every Estimate
Averages are useful, but your event is not average. Several factors push consumption higher or lower, and ignoring them is where most hosts get caught out.
- Time of year: Summer events, particularly outdoor weddings and garden parties, see higher consumption of cold drinks like beer, cider, and spritzes. Winter events lean heavier on red wine and spirits, but overall volume per head tends to be slightly lower.
- Demographics: A corporate networking event on a Tuesday evening will see far less consumption than a Saturday night 40th birthday. Guests who are driving home drink less. Events with a younger crowd skew towards cocktails and shots.
- Bar style: A cocktail bar with a curated menu naturally paces consumption because drinks take longer to prepare. A self-serve setup or open beer-and-wine bar sees faster throughput.
- Free bar vs cash bar: This is the big one. A fully hosted bar increases consumption by roughly 20 to 30 percent compared to a pay bar. If you are running a tab with a cap, expect something in between.
- Food: A substantial sit-down meal absorbs alcohol and slows drinking. Canape-only receptions without a meal see noticeably higher bar traffic throughout the evening.
The Soft Drinks Question Nobody Asks Early Enough
A common mistake is calculating alcohol and forgetting that 15 to 20 percent of your guests will not be drinking at any given time, whether they are pregnant, driving, on medication, or simply choosing not to. Budget for at least 20 percent of your total drinks order to be non-alcoholic, and make those options genuinely appealing. Sparkling elderflower, alcohol-free gin and tonics, or a proper mocktail menu will be far more appreciated than a sad jug of orange squash on the end of the bar.
What Happens to Leftover Stock
If you are supplying your own drinks through a self-serve bar or working with a mobile bar provider on a supply-your-own basis, leftover stock is your responsibility. Unopened bottles of wine and spirits can usually be returned to most retailers if you keep the receipt and they are in sellable condition. Opened bottles cannot. A smarter approach is to slightly under-order on wine and spirits, knowing you can top up with a quick run, and over-order on beer and soft drinks since they keep well and are inexpensive to store.
If you are using a fully stocked mobile bar service, this headache disappears entirely. The provider manages stock levels, adjusts in real time based on what guests are actually drinking, and you pay only for what is consumed.
Why Getting Professional Help Takes the Guesswork Out
The real value of working with an experienced mobile bar team is not just the bar itself. It is the consultation beforehand. A good provider will ask about your guest count, event duration, audience, venue, food plan, and bar style, then build a drinks estimate tailored specifically to your event rather than relying on generic ratios.
At Viva Bar Hire, drinks planning is part of every booking, whether you are hiring a fully staffed cocktail bar for a wedding, a sleek gin bar for a corporate summer party, or our self-serve Bar in a Box for a more relaxed celebration. We handle the maths, manage the stock, and make sure your bar never runs dry and your budget never runs away. Get in touch through vivabarhire.co.uk to chat through your event and get a tailored drinks estimate with no obligation.