You have finalised your guest list at 120, booked the marquee in the Cotswolds, and now your partner has turned to you with the question that derails every couple at some point: how much alcohol do we actually need? Too little and your best man is queuing at an empty bar by 9pm. Too much and you are hauling crates of untouched Sauvignon Blanc back to the garage on Monday morning. Getting drinks per head right is part maths, part psychology, and part knowing your crowd - and it is far less daunting than it sounds once you break it down.
The Golden Rule: One Drink Per Person Per Hour
The drinks industry standard that most caterers and bar professionals work from is beautifully simple: budget for roughly one drink per guest per hour. For a wedding reception that runs five or six hours from the welcome drinks through to the last dance, that means five to six drinks per person across the entire evening.
But that is only the starting average. Several real-world factors push the number up or down:
- Time of year. Summer weddings see higher consumption of lighter drinks - prosecco, gin and tonic, cold lager - and guests tend to drink a touch more when the sun is out. Winter receptions lean toward red wine, whisky, and warming cocktails, often at a slightly slower pace.
- Day versus evening. An afternoon reception that wraps up at six will average closer to one drink every 90 minutes. An evening-only celebration with a DJ and a late licence will comfortably hit one per hour or more.
- Your guest demographic. A crowd of university friends in their twenties will drink differently to a gathering that includes grandparents, children, and designated drivers. Be honest about your guest list - nobody is judging, but it does affect the numbers.
- Whether a meal is served. A sit-down wedding breakfast slows consumption during the meal itself. A standing canape reception keeps people near the bar more consistently.
Breaking It Down by Drink Type
Knowing the total number of drinks is helpful, but you also need to know the split. A useful breakdown for a typical UK wedding of 100 to 120 guests looks something like this:
- Welcome drinks: One glass of fizz or a signature cocktail per person on arrival. For 120 guests, that is roughly 20 bottles of prosecco (six glasses per bottle) or one large batch cocktail.
- Wine with the meal: Half a bottle of wine per person during the wedding breakfast. That means around 60 bottles split roughly 60/40 between white and red, though summer weddings often skew 70/30 towards white and rose.
- Evening bar: This is where the real variety kicks in. Expect a mix of beer, spirits, cocktails, and soft drinks. A good rule of thumb is that around 20 percent of your guests will stick to soft drinks or water at any given point in the evening, so factor that into your quantities.
- Toast: One glass of fizz per person. Another 20 bottles, or swap to a signature cocktail if that suits your style.
If these numbers feel overwhelming to manage yourself, that is precisely why many couples hand the entire process over to a professional mobile bar service rather than attempting a DIY drinks table.
The Self-Serve Temptation (and When It Works Brilliantly)
Some couples prefer to supply their own alcohol - perhaps a favourite wine from a holiday or a craft beer they love - and set up a help-yourself station. This can work wonderfully for smaller, relaxed celebrations, especially if your venue permits it. The key risk is that self-serve bars make it almost impossible to track consumption in real time, so you are more likely to either over-buy or run short.
A middle-ground option is a self-serve package like a Bar in a Box, which gives you the physical bar setup, glassware, and equipment without staffing, so you keep control of the drinks while still presenting something that looks polished and intentional rather than a wobbly trestle table with a bedsheet over it.
Why a Staffed Bar Takes the Guesswork Away
The simplest way to nail drinks-per-head calculations is to let someone else do it entirely. A professional bar team will ask you all the right questions - guest count, event duration, time of year, meal format, and your crowd's likely preferences - and then build a drinks plan around the answers. They manage stock in real time, adjust if a particular drink is flying or sitting untouched, and ensure the bar never runs dry.
Staffed bars also pour consistently, which sounds minor but matters enormously. A generous uncle free-pouring gin at a self-serve station will get through a bottle in eight drinks. A trained bartender will make it stretch to the standard 25 or so measures.
Get the Numbers Right Without the Stress
If you are knee-deep in spreadsheets trying to calculate units per head and bottles per case, take a breath. At Viva Bar Hire, we handle this conversation every single week for weddings of every size, style, and setting across the UK. Whether you want a fully staffed cocktail bar, a prosecco station, or a self-serve Bar in a Box with all the kit and none of the staff, we will help you land on the right quantities so you can stop counting bottles and start looking forward to the day. Drop us a message through vivabarhire.co.uk and let us do the maths for you.