How to Calculate the Amount of Alcohol Needed for a Party

Guests are coming over and it's time to go shopping. How many drinks do you actually need?

As a seasoned caterer, the No. 1 question that clients ask is, “How much booze should I buy for a party?”

In the past, my answer never changed: 30% spirits, 30% wine, 30% beer, and 10% soft drinks. However, in recent years, more and more guests have begun to re-evaluate their relationship with alcohol. Many seek alternative nonalcoholic options beyond the old standards like Coke, Diet Coke, and ginger ale.

Let’s break down the math I use for clients to determine the total drinks needed for a party, and how much of each to purchase. If the math feels overwhelming, there are also a few tricks that keep things simple.

My new recommendation for serving any large group is 30% spirits, 30% wine, 15% beer, and 25% soft drinks. As many people take a “flexitarian” approach to drinking, guests will often alternate between alcoholic and nonalcoholic pours throughout the evening — almost like chasing a shot, but over a longer period of time.

Ultimately, you know your friends and family best. Think of the times you’ve hung out at a bar or party. What are their go-to drinks? Do they like to indulge, or slowly nurse what’s in their glass? If no one in the group ever seems to drink rum, skip it. The day of the week can also determine how guests will hit the bar cart. Scale back the total by 10% if you meet on a “school night.”

Related: The Soda Aisle Has Never Been More Exciting — Here Are 6 Brands to Try

How much alcohol should you buy per guest? (Caution: math ahead)

To calculate the total number of drinks needed for a party, multiply the number of guests (G) by the number of hours of party time (T). Multiply that figure by the number of drinks per hour (DPH). The average party guest consumes around 2 drinks per hour. Feel free to adjust that number up or down if you don’t feel it’s true for your group.

(G x T) x DPH = total number of drinks.

Next, calculate what percentage of your total drinks should be devoted to wine, beer, spirits, and soft drinks. For example, a party of 10 people that meet from 6 to 9 p.m. would need a total of 60 beverages. Using the percentages recommended above, that would equal 18 spirit pours, 18 wine pours, 9 pints of beer, and 15 soft drinks. Adjust the numbers if your crowd favors one option more than others.

Quick tips on buying alcohol for a party

1. Narrow the options. Buying larger-sized bottles of a single spirit is cheaper than buying standard bottles of multiple liquors.

2. Choose one or two headliner spirits or signature cocktails. If averaging 1 1/2 ounces per pour, you can expect 16 shots, or around 12 mixed drinks, from a 750mL bottle.

3. Canned cocktails or spritzers can save on cleanup. These can also be easily dressed up with self-served cocktail cherries and separate cups with ice.

4. Stock one red and one white wine. If the party is large enough, order bottles in multiples of 12 to likely receive a case discount from your local wine shop.

5. Consider a pony keg. A pony is a quarter of a keg and will serve around 60 pints — 20 drinks per hour for a three-hour party. It’ll cut down on cleanup, recycling, impress beer nerds, and is the most sustainable option.

6. Simple, nonalcoholic spritzes will keep drinks accessible. Mix a can of plain seltzer with 1 ounce of flavored syrup or 2 ounces of fruit juice for a quick and easy winner.

7. Double your ice. Always ensure you stock two batches of ice — one for chilling cans and bottles, and the other to serve in drinks.

Don’t just guess, ask

Much like a wedding invite may ask, “Chicken or fish?,” find out what guests would like to drink. These days, online RSVP systems make it easy. Comment sections or surveys can be added to most invites.

My biggest budget-saving trick is to narrow the options. It costs less to buy a larger bottle of a single spirit than three different ones. Make one batched signature cocktail or serve a single wine. If you’re unsure of who will partake, make a big batch of punch or lemonade and have an alcoholic supplement like whiskey or vodka on the side so people can spike their glass if they choose.

Since you’re likely to be hosting a small party (and not, say, a wedding), you won’t be expected to stock a fully operational bar. Choose one or two headliner spirits or cocktail recipes, and keep in mind that most bottles come in 750-milliliter and 1-liter sizes. A shot is 1 1/2 ounces, which gives you around 16 shots or 12 mixed drinks from a 750mL bottle.

If you don’t want to mess with recipes or measuring, grab canned cocktails or spritzers. They can be fancied up if you pour them into a glass over ice and garnish with a maraschino cherry.

Related: We Tasted 17 Canned Cocktails — Here Are Our Favorites

For wine, cover your bases with a red and a white, or maybe a rosé or orange wine if it’s warm out. You can get five 5-ounce pours from a standard 750mL wine bottle. Magnums are 1.5L and yield about 10 pours. Also, ask your local shop about a case discount, often given to those who buy 12 bottles or more. If you’re planning a toast, consider smaller pours, at 2 ounces each. That will get 12 glasses from a 750mL bottle, or six from a 375mL half-bottle.

Beer commonly comes in packs of 6, 12, and 24. Reduce waste and impress your beer-loving friends by grabbing a sessionable pony keg from a local brewery. A pony is one-quarter of a keg and serves roughly 60 pints, or 20 drinks per hour for a three-hour party. Ask if the brewery will provide a tub to chill the pony (these are also available at most hardware stores).

Nonalcoholic (N/A) options are plentiful these days. A typical bar stocks cranberry, grapefruit, lemon, lime, and pineapple juice. Think about what could pair well with your chosen spirits, but which could also be enjoyable alone over ice.

For an easy N/A spritz, mix a can of plain seltzer with 1 ounce of flavored syrup or 2 ounces of fruit juice like blood orange, mango, apple cider, or my favorite, POG, a blend of passion fruit, orange, and guava juices. Play around with different teas, tepache, and N/A spirits, too.

The most forgotten item during the scramble of party hosting is ice. Grab two bags of ice, one for chilling drinks and the other for putting in drinks. Make sure you have the right tools on hand like coolers, an ice bucket, and tongs.

I’m guilty of running around too much at a dinner party, but I’ve learned that delegation is key. When you forget to buy something, text a friend who is running late to pick up anything you missed or need. You’ll get help, and they’ll get to save face for not being on time.