How much alcohol to buy for a wedding (without over-ordering)

You are hosting a 100-person wedding reception and the venue asks how much alcohol to bring. Guess too low and the bar runs dry during toasts; guess too high and you are storing four unopened cases of beer in your garage for a year. The honest answer is not a flat "one drink per person per hour" rule of thumb — it depends on how many guests actually drink, how long the event runs, how quickly people drink at a wedding specifically, and how you split the bar between beer, wine, and liquor. Run the real numbers and the shopping list falls out of them.

Start with who is actually drinking

Not every guest at the reception drinks. Some are designated drivers, some are pregnant, some do not drink at all, and some are children counted in the guest total but not the bar count. A reasonable planning figure is that around 85 percent of adult wedding guests will have at least one drink over the course of the night — lower if your crowd skews older, dry, or family-heavy; higher for a college-friends open bar. Apply that percentage to your guest count first, because every calculation after this point should be based on drinking guests, not total guests.

Pace drinks to the length of the event

A wedding is not a nightclub. Guests are also eating dinner, sitting through toasts, taking photos, and dancing, so consumption is slower and more uneven than a straight "one drink per hour" estimate suggests — most of the drinking happens at cocktail hour and during the reception's open dancing, not steadily across the whole event. A pacing rate of about 0.85 drinks per drinking-guest per hour is a reasonable average across a typical four-to-six-hour wedding, front-loaded toward cocktail hour and tapering during dinner. Multiply drinking guests by hours by that pacing rate and you get the total number of standard drinks the event needs — the single number everything else is split from.

Split the total across beer, wine, and liquor

Most receptions do not serve one thing; they offer a mix, and the mix should reflect your crowd and your bar style. A common starting split is roughly 40 percent beer, 35 percent wine, and 25 percent liquor, though a wine-forward crowd or a full cocktail bar will shift those numbers considerably. Whatever three percentages you pick, they only need to be proportionally right — a calculator can normalize them to sum to exactly 100 percent for you, so 45/40/25 and 36/32/20 produce the identical split once scaled.

Convert drinks into bottles and cases

Once you know how many beers, glasses of wine, and cocktails the event needs, convert each into what you actually buy at the store, using standard bar-service pour sizes:

• Beer — a standard serving is 12oz, and beer is sold by the case of 24, so divide total beer servings by 24 and round up.
• Wine — a standard pour is 5oz, and a 750ml bottle holds about five of those pours, so divide total wine servings by 5 and round up.
• Liquor — a standard cocktail pour is 1.5oz, and a 750ml liquor bottle holds about 25.4 fluid ounces, so multiply liquor drinks by 1.5, divide by 25.4, and round up.

Rounding up matters more than it looks: you cannot buy 4.8 cases of beer, and buying short by a fraction of a case is how a bar runs dry at 10pm.

Worked example: 100 guests, four-hour reception

Take 100 guests, 85 percent of whom drink, over a four-hour reception, at a pacing rate of 0.85 drinks per drinking-guest per hour, split 40/35/25 across beer, wine, and liquor:

• Drinking guests: 100 times 0.85 equals 85.
• Total drinks: 85 times 4 hours times 0.85 equals 289 standard drinks.
• Beer: 289 times 40 percent equals about 116 servings, or 116 divided by 24 equals 5 cases.
• Wine: 289 times 35 percent equals about 101 servings, or 101 divided by 5 equals 21 bottles.
• Liquor: 289 times 25 percent equals about 72 drinks; 72 times 1.5oz divided by 25.4oz equals about 5 bottles.

Add ice on top — a simple planning figure is 1 pound of ice per guest, covering both drink chilling and any drink service, which for this event is 100 pounds.

Buy a little more than the math says

The numbers above are a planning floor, not a hard ceiling. Most liquor stores and many venues will let you return unopened bottles and unbroken cases, so there is little cost to rounding the shopping list up rather than down — the real cost is running out. Nudge the drinking-guest percentage or pacing rate up if your crowd is younger or the reception runs long into the night.

Open bar versus cash bar changes the pacing rate

Everything above assumes an open bar, where guests do not weigh cost against each additional drink. A cash bar changes consumption meaningfully — guests self-ration, so a lower pacing rate is more realistic, while a limited-hours open bar that switches to cash after dinner effectively shortens the hours you should plan full pacing for. If your venue is doing a hybrid — open bar for cocktail hour, wine service only at dinner, cash bar afterward — it is worth running the calculation separately for each phase rather than treating the whole night as one uniform rate.

Signature cocktails deserve their own line item

A house cocktail or two adds a nice personal touch, but do not fold it into the general liquor percentage — signature drinks get ordered disproportionately more than a standard mixed drink because they are the "fun" option guests want to try, sometimes even by people who would otherwise have stuck to beer or wine. Estimate a signature cocktail separately, at roughly one per interested drinking guest over the course of the event, and buy the specific spirits and mixers it needs as their own small-batch purchase rather than assuming your general liquor bottles will cover it.

Do not forget non-drinkers and mocktails

Guests who do not drink alcohol still want something to hold at cocktail hour and during toasts, and an afterthought pitcher of ice water does not read as hospitality at a wedding. Plan a non-alcoholic option — a mocktail, a flavored soda, or sparkling water with garnish — sized at roughly one serving per non-drinking guest per hour, using the same guest-count-times-hours logic as the alcohol math, just applied to the percentage of guests who are not drinking rather than the percentage who are. It is a small, cheap addition that closes an easy-to-miss gap in an otherwise carefully planned bar.

If the venue requires you to bring your own alcohol (a common arrangement at private venues, parks, and some banquet halls), confirm the corkage or bartending-service fee before finalizing quantities, since some venues charge per bottle opened rather than per bottle purchased — which changes the calculus toward slightly larger bottles and fewer of them, rather than a wide variety in small formats.

Doing this arithmetic by hand for every guest-count scenario gets old fast, especially once you start adjusting for a longer cocktail hour or a heavier-drinking crowd. Our wedding and party alcohol calculator takes your guest count, event length, drinking percentage, pacing rate, and beer/wine/liquor split, and returns the exact cases, bottles, and ice you need to buy — so you can stock the bar with confidence instead of a guess.