You have confirmed sixty guests, booked the venue, and chosen a stunning cocktail menu. Then someone asks the question that quietly haunts every event host: how much alcohol should we actually buy? Order too little and the bar runs dry at nine o clock. Order too much and you are left with forty untouched bottles of Aperol gathering dust in the garage. Getting drinks-per-head right is one of the most practical yet overlooked parts of event planning, and it makes a bigger difference to your budget and your guests' experience than almost any other detail.
The Baseline Formula Most Planners Use
The drinks industry rule of thumb for a standard evening event is roughly one drink per person per hour for the first hour, then one drink every ninety minutes after that. For a five-hour evening reception with eighty guests, that gives you somewhere around 280 to 320 individual servings. It sounds straightforward, but the reality is messier. Your crowd's drinking habits, the style of event, the time of year, and even the day of the week all shift those numbers considerably.
A Friday-night corporate Christmas party where everyone arrived straight from work will burn through stock faster than a Sunday-afternoon christening. A summer garden party with Pimms and prosecco tends to encourage steady, lighter drinking over many hours, while a cocktail-focused evening can slow consumption because each drink takes longer to prepare and savour. Knowing your audience matters far more than memorising a formula.
Factors That Push the Numbers Up or Down
- Event type: Weddings typically see higher consumption than corporate networking events. Milestone birthdays, especially 30ths and 40ths, tend to be heavier sessions. Hen dos with butlers in the buff serving drinks can spike early consumption thanks to sheer excitement and novelty.
- Time of day: Afternoon events that start at two and wind down by seven will use roughly thirty percent less per head than an evening event running until midnight.
- Season and weather: Hot summer days increase demand for chilled beer, spritzers, and soft drinks. Winter events lean toward richer cocktails and red wine, often in slightly lower volumes but higher cost per serve.
- Drink style: A self-serve prosecco wall or beer fridge encourages faster consumption than a staffed cocktail bar where guests queue for hand-crafted drinks. If you are using a Bar in a Box setup for DIY serving, factor in roughly ten to fifteen percent more stock than you would with a staffed bar, because guests tend to pour more generously than a trained bartender.
- Non-drinkers and drivers: Always estimate that ten to twenty percent of your guest list will stick to soft drinks. That proportion has been rising year on year, so a strong mocktail and alcohol-free beer selection is no longer optional.
A Worked Example for a Wedding With 100 Guests
Suppose you are hosting a summer wedding with a drinks reception from three, a meal at five, and evening celebrations until midnight. Here is a rough breakdown:
- Drinks reception (3pm to 5pm): Two drinks per person. That is 200 servings, typically prosecco, a signature cocktail, or a soft alternative.
- Dinner (5pm to 7pm): One to two glasses of wine per person, so roughly 150 glasses. Half a bottle of wine per guest is a reliable starting point for a seated meal.
- Evening bar (7pm to midnight): Three to four drinks per person across five hours. Around 350 servings, split between cocktails, beer, wine, and soft drinks.
That totals roughly 700 servings across the day. In practice, an experienced bar team will monitor pace and adjust. A professional mobile bar service will also advise you before the event based on your specific guest profile, which saves guesswork and wasted spend.
What Happens to Leftover Stock
One of the most common worries is paying for drinks that never get opened. If you are supplying your own alcohol through a dry-hire or Bar in a Box arrangement, any unopened bottles remain yours. Many couples keep leftover wine for anniversaries or gift bottles to the bridal party. With a fully staffed and supplied bar package, a good supplier will discuss sale-or-return options upfront so you are not left footing the bill for surplus stock. Always clarify this before signing any contract.
Why Professional Advice Beats Guesswork
Online calculators give you a starting point, but they cannot account for your uncle who only drinks real ale, your university friends who will order espresso martinis all night, or the fact that half your office are doing Dry January. A conversation with an experienced bar team will refine those numbers quickly and confidently, often saving you money compared to an anxious bulk-buy at the cash and carry.
If you are planning an event anywhere in the UK and want honest, specific advice on quantities, bar style, and budget, get in touch with Viva Bar Hire. Whether you need a fully staffed cocktail bar, a self-serve Bar in a Box, or simply a quick chat about how many bottles of fizz to order, the team at vivabarhire.co.uk will help you get it exactly right without the morning-after regret of over or under ordering.