You’ll need to make some decisions concerning the beverages you want to serve, then you can decide how much to buy. Would you prefer to serve wine and beer with an assortment of nonalcoholic choices? Or do you intend to offer a full bar with mixed drinks and specialty cocktails?

A Casual Gathering

Especially for casual gatherings, it’s perfectly acceptable—and may be the preferred approach—to serve only wine, beer, and nonalcoholic drinks. Most guests will find a satisfying option, and for the hostess, a limited alcohol selection simplifies planning and allows you to match the beverage options to your menu. This simple guide helps you decide how much liquor and how many nonalcoholic drinks you should have to satisfy your party guests. Get our free take-along chart to help you make smart decisions when you’re shopping for party drinks. When shopping for your party, include these beverages on your list:

White wineRed wineBeerWater: mineral and bottledSoft drinks: lemon-lime, diet lemon-lime, cola, and diet cola

Customize the list to suit your guests’ preferences or to match a theme. For example, you may want to include a sparkling wine for a special celebration, or focus on specialty beer choices for guests with sophisticated palates. Also, you’ll want to provide nonalcoholic choices, such as bottled water, juices, lemonade (like this tasty homemade lavender lemonade), iced tea, soft drinks, or nonalcoholic beer and wine.

Offering a Full Bar

Obviously, hosting a complete bar will require more thought and investment. If you already have a home bar, you may have a foundation of spirits, mixers, and accents. You’ll need to review your inventory to avoid skimping on party favorites or duplicating purchases (a small bottle of bitters or vermouth goes a long way). For a full party bar, include these elements on your list:

Wine: red and whiteBeerBourbonGinRumScotchTequilaVodkaWater: mineral and bottledSoft drinks: lemon-lime, diet lemon-lime, cola, and diet colaTonicClub sodaJuices: orange, cranberry, and tomato

In addition to these basics, if you’re making a signature cocktail (these are our favorite classic cocktails) or know your guests’ favorite drinks, add the appropriate ingredients to your shopping list. Editor’s Tip: If you plan to offer a full bar, check that you have the necessary tools and appropriate glassware—if you’re hosting an outdoor gathering, consider disposable wine glasses ($8 for 32, Party City) that won’t break if they’re dropped. You’ll also want to be sure you have the appropriate ingredients to mix and serve a variety of cocktails.

Check Your Guest List

When it comes to knowing how much you need, the number of guests is the primary determining factor. If you know your guests’ preferences on drinks (beer, wine, spirits, or soft drinks), you can calculate what you need accordingly. If you’re unsure about people’s preferences, purchase a variety of beverages with some to spare. Ask your beverage store if you can return unopened bottles. Even if you can’t return them, most unopened bottles will keep long after the party, so you don’t need to be concerned about waste. If you entertain frequently, you may want to shop in quantity to get discounts on large purchases To help you with the calculations, we’ve made the party math simple. Our free Beverage Quantity Guide, available below, offers shopping recommendations for each item you’ll need, based on guest count. Whether you have six guests or 50, the chart lists how much of each beverage you’ll need. It provides separate information for casual parties serving only wine and beer, as well as for parties that offer a full bar.

If You Estimate on Your Own

If you’d prefer to make your own estimates, start with these party assumptions:

Nonalcoholic beverages: Assume guests will drink two servings in the first hour and one for each additional hour of the party. If the weather is warm, expect people to drink a bit more.Wine: One 750-milliliter bottle of wine provides five to six glasses, depending on your pour. During a party, plan one bottle for every two guests.Beer: Estimate that guests will drink about 12 ounces (one bottle) every half hour to hour during the party.Cocktails: Allow one and a half ounces of liquor for each drink. A 750 milliliter bottle (a fifth) makes about 16 drinks. Figure about a quart of mixer for every three guests.

Remember, not every guest will want every option you offer. Our Beverage Quantity Guide is an easy tool to get the right combination for most parties.

Stock Party Supplies

Along with the beverages, you’ll need additional items, like ice, garnishes, glasses, and napkins. Add these items to your shopping list and you’ll be well-stocked with the essentials. Buy ice. You’ll need one and a half to two pounds of ice per guest to keep beverages chilled. Fill a large outdoor cooler ($40, Target) or an aluminum beverage tub ($25, Target) with ice if you don’t have room in the freezer. Keep coolers conveniently near the drink stations or bar, and be sure to keep ice for glasses separate from the ice used to chill bottles and cans. When planning your party, here’s a good estimate of how much ice you’ll need:

6 guests = 10 pounds12 guests = 24 pounds25 guests = 50 pounds50 guests = 100 pounds

Purchase or rent glasses. Whether you’re using real glassware ($3, Crate & Barrel) or disposable, expect guests to use multiples. Start with these estimates:

6 guests = 16 glasses12 guests = 30 glasses25 guests = 75 glasses50 guests = 150 glasses

Remember cocktail napkins. Even if you’re only serving food at the table, cocktail napkins protect furniture, mop up minor splashes, and keep guests’ hands clean. Plan for the following number of napkins:

6 guests = 24 napkins12 guests = 48 napkins25 guests = 100 napkins50 guests = 200 napkins

Choose your garnishes. Especially if you’re offering a full bar, you’ll want to add finishing touches to mixed drinks. If you’re only offering beer and wine, consider including slices or wedges of citrus fruits, such as limes and oranges; they’re a pleasing addition to certain beer selections. Consider these popular garnish options:

OrangesLemonsLimesCherriesPineapplesGreen olivesCocktail onionsFresh herbs, such as mint, basil, or rosemary

Follow these tips to make planning drinks for your party an easy and stress-free experience.