Calculate Enough Alcohol for a Party of Any Size 

You'll never run out of alcohol at a party again with these calculations that take the guesswork out of your party planning.

Published December 5, 2022
Group of friends clinking glasses while enjoying a party

You have your planner propped open in front of you or your laptop open to the applicable month as you daydream of your upcoming party. Be it a holiday shindig, a midsummer BBQ, an elegant birthday bash for your favorite Taurus, or a cozy engagement party for a dear friend, you don't want to run out of alcohol. Whatever the reason for the gathering, you'll need a well-stocked bar. Take the guesswork out of all your party planning with this handy guide to calculating alcohol for a party.

How to Calculate Alcohol for a Party

When calculating alcohol for a party, there are many variables at play. But don't worry, there's no need to pull out your old graphing calculator from high school. At most, you'll just need your phone's calculator app if mental math isn't a strong suit. You can put those one-minute multiplication test nightmares to rest. To be more precise with your calculation, you only need to know three variables:

  • Number of guests attending
  • How long your party is
  • What type of alcohol you plan to serve

Expect each guest to tip back two to three drinks for every two hours of the party. Of course, if you only offer beer or wine, you'll want to have more of each than if you were offering liquor, beer, and wine.

  • Number of guests x 2 drinks x length of party in hours ÷ 2 = total drinks
  • Number of guests x 3 drinks x length of party in hours ÷ 2 = total drinks

For instance, a four-hour party with around ten guests will require approximately 40 drinks (10 x 2 x 4 ÷ 2) or up to 60 drinks (10 x 3 x 4 ÷ 2), all depending on just how much your group usually sips.

How Many Bottles to Buy

If you're only serving one type of drink, it's pretty easy to calculate exactly how many bottles you'll need based on 2 to 3 drinks per person every two hours. First, determine how many drinks. Then, divide it by how many servings are in a bottle.

Servings per Bottle Infographic

A traditional bottle of wine, 750mL, will yield 5 servings of 5 ounces each. Easy math! The number of bottles of wine will vary depending on if wine is the supporting star at a dinner party or the star of a wine and cheese or wine-tasting party. If you're serving up bubbly, you can expect a traditional bottle of Champagne or prosecco to contain approximately 6 servings, although if you're only having a toast, then you can use a half glass or so and stretch out the bottle.

It may seem tricky, but you can still calculate the number of servings you can get from a bottle of liquor!

  • While drink recipes do vary between 1½ to 2 ounces of liquor per recipe, err on the side of 1½ ounces of liquor per mixed drink for your gathering.
  • A 750mL bottle of liquor will have approximately 17 servings when using 1½ ounces, or 13 servings if you or your guests pour with a heavy hand and use 2 ounces.

Beer is the easiest when you're using a traditional single-serve bottle or can. Beer is usually a serving size of 12 ounces, but this can change depending on the alcohol by volume (ABV).

Calculate Different Types of Liquor for a Party

What if you're serving a combo of wine, beer, and liquor-based cocktails? Break down the number of servings per bottle of wine, liquor, and beer.

Guests will typically drink around 1½ to 2 drinks per hour, consuming more in the first hour or two and tapering as the party continues. To satisfy the 1½ to 2 drinks per hour, use 1.25 drinks per hour per guest and round to the nearest number because you won't be buying bottles in fractions. Don't forget to include yourself in the total guest count!

How to Calculate Drinks for a Party

To Calculate Spirits

If you're offering beer, wine, and spirits, generally about 30% of your guests will be drinking spirits and cocktails. When calculating the number of bottles required, it's assumed that half your guests will drink wine (which is why you multiply the guests and hours by 50% or 0.5), 30% will drink beer, and 20% will enjoy a mixed drink. To calculate:

Number of guests x 1.25 x .3 (30%) ÷ 16 = bottles per hour

To Calculate Wine

Assuming you're also serving cocktails and beer, around half of your guests will likely drink wine. To calculate the wine:

Number of guests x 1.25 x .5 (50%) ÷ 5 = bottles per hour

To Calculate Beer

Assuming you're also serving cocktails and wine, around 20% of your guests will likely drink beer. To calculate the beer:

Number of guests x 1.25 x .2 (20%) ÷ 1 = bottles per hour

If You're Not Serving All Three

Don't panic if you know you won't be supplying one of these three types of liquor or if you know your guests will want beer more than they'll want wine. So long as the percentage of wine, beer, and spirits add up to 100%, then you're good to go. If you're only serving wine and beer, expect it to be a 75% and 25% split and adjust accordingly, multiplying by .75 (wine) and .25 (beer) respectively.

Consider these alternatives for a 3-hour small summer BBQ with only 12 people or a 5-hour larger party with 30 people.

Calculating Drinks for a Party Example

If only one bottle of wine for a BBQ makes you nervous, you can grab two or more. Remember, you know your guests and party best. For the dinner party, if the focus is on wine and liquor, you can take a lower average for beers.

As for mixers, you'll need approximately one quart or liter for every three guests. You have 10 guests? Round up and buy 4 quarts or liters of mixers. You can go with a spread of mixers or keep it simple with mostly club soda, tonic, and soda with smaller amounts of juice.

Key Considerations in Calculating Alcohol for Your Party

When doing the due diligence in planning your party, a few factors can influence how stocked you'll want your drink station or what you'll even want to fill it with.

  • What time? First, consider the time of the party. A brunch party won't require as many cocktails as a dinner party.
  • Who's coming? Are your friends big drinkers? You'll probably want more. Have a lot of nondrinker or moderate drinker friends? You may not need as much. If the party is for families, you will probably need less alcohol than if it's an adults-only shindig.
  • How long? Another easy factor to consider is the length of the party. If you're only hosting people for a quick hour or two, you won't need to have as many supplies as a party that lasts five or six hours.
  • How many? All that means nothing if you don't account for how many guests will be in attendance.
  • What type? A all-night rager is probably going to require more alcohol than an open house where guests can come and go as they please. If it's a cocktail party, well, you're going to go through far more cocktails than if you're hosting a dinner party.
  • What's on the drink menu? Consider the variety of beverages you'll be offering; will you be focusing on wine? Then you'll need less beer or cocktails.

Most importantly, know your guests, whether they will prefer beer over cocktails, and if they're heavy drinkers or if they will only have a half glass or so.

How to Make Buying Alcohol Easier

You get to decide whether you even want to provide your guests with all three options of wine, beer, and spirits or if you want to suggest very specific cocktails for your guests to make. For a smaller soiree, you can easily have a wide selection and variety on hand since you don't need to purchase dozens of bottles. But that choice is entirely up to you, especially if you want to offer a selection of wines; you can offer just a little bit of beer or a smaller bottle of liquor.

Make your hosting duties easy by focusing the use of the liquor on a signature cocktail or two. Keep it simple! A good place to start is with a classic highball, think a vodka soda, and then add a simple touch such as a splash of cranberry juice or pineapple juice. You can appeal to more guests by giving rum as an option as well. With two liquors and three mixers, you can have a dozen drink options right away. Don't forget the citrus wedge garnish. If you don't want your guests to mix up their own drinks, consider making up mixes ahead of time, such as three gallons of margarita mix, pitchers of flavored margaritas, or tasty punches to satisfy any group.

Tips for Calculating Alcohol for a Party

If your palms are sweaty because you're still overwhelmed and don't know what to do, take a breath, pour yourself a glass of wine, and let these final tips be the garnish in your party-planning adventure.

  • Always round up when you're calculating how many bottles or servings you'll need. And if you're still not sure if 2, 4, or 12 bottles will be enough, you can always grab some extra. Put those unopened, or opened, bottles to good use, enjoying them on your own or in your cooking. Or you can gift the extra bottles. But only gift the unopened bottles.
  • Remember: know your audience! A baby shower won't necessarily need as much alcohol as a birthday party or holiday bash, but every family and friend group is different. No judgment here.
  • Don't forget the ice! You'll need a half pound of ice per mixed drink or a cup of ice per drink. This isn't a hard and fast rule, but no one wants a warm drink. If you know you'll have 16 servings of a signature highball cocktail, go ahead and make sure you have 8 cups or 8 pounds of ice. Easy enough!
  • If you're not sure how much you'll need for a signature cocktail recipe, such as a rum and cola or Paloma, multiply your ingredients by the number of servings, then boom! You know how much you need. Don't forget to account for the garnish!
  • Having enough glassware on hand can be tricky, but often you can pick up a few odds and ends from a local second-hand store. Just be sure to wash before using them.
  • Consider the timing, the age range, and the occasion as you make decisions of what you'll serve and how much.
  • Don't forget to account for food and snacks! You'll want your guests to be well fed, and be sure to have water or nonalcoholic mixers available to hydrate.

Popping Bottles for a Party

Grab your heels or your slippers, get out your glassware, and don't forget to send out the invites. You're armed with the knowledge of how to have a well-stocked bar at any party you throw. There's no time like the present to put that new skill to use.

Calculate Enough Alcohol for a Party of Any Size