That’s another question we get every day. Like so many questions, it’s just using basic principles with simple math. I start by figuring how many drinks I’m going to serve. I get that by multiplying the number of guests by the length of the party in hours (I estimate 1 drink per person per hour). Now, for most parties, about 40% of the drinks served will be beer, which in today’s standard will be drunk straight from the bottle or can and eliminates the need for a glass. The next question is whether there will be staff help picking up and washing glasses as the party continues. This will save glasses. If you have staff help, reduce the number of glasses by 25%. If not, reduce the number of glasses by 10% (some people will ask to refill their current glass). The next question is how many and what kind of glasses? There are 4 kinds of glasses: wine glasses, bar glasses, all purpose glasses and specialty glasses, such as martini, champagne, or brandy. I leave the specialty glasses out of the computation because they are usually for some signature drink and specific purpose such as a toast. For these, you should figure needing 1 glass for 75%-100% of your guests, excluding children. For the bulk of the glasses, I figure 60% wine glasses, 30% all purpose glasses and 10% bar glasses. The wine glasses are strictly for wine, nothing else. The bar glasses are for your hard liquor drinks: scotch, whiskey, etc. All purpose glasses serve as glasses for the occasional beer drinker that wants it in a glass, water, sodas etc. Because they are stemmed, they also serve as a wine glass when you run out of wine. Many of our clients actually rent only the all purpose glasses. It certainly makes the math easier. Becuase the glasses only come by the rack, it takes away much of the guess work.
An example may make it easier to understand. Let’s say I’m having a wedding reception that will last 3 hours and I’m expecting 150 guests. I’m also planning to have a champagne toast to the bride and groom when they first appear. I’m only buying enough champagne for that and am not planning to serve it after that. I have a caterer that will be picking up the used glasses and rinsing them throughout the party. According to the formula, I will probably serve 450 drinks, about 180 of them beer. That brings me to 270 drinks. I have staff, so I can reduce that to 202. 60% of those will be wine, so I want 125 wine glasses(they come in racks of 25); 30% all purpose- 75 and 25 bar glasses (12 oz double old fashioned). For the champagne toast, I’m going to have the caterer circulate staff with the champagne served in fluted champagne glasses. Many people don’t like champagne, so I figure I’m going to have enough for 75% of the guests. That means I need 3 racks of 36 (108 total) for my 175 guests. As longs as the bar is open prior to the toast, I should have plenty. If I have extra, I will serve it at the bar until it runs out. I have assumed all adults in this example. If I have a large number of children included in the guest count, I would shift 1 or 2 racks of wine to the all purpose. While this will probably result in some unused glasses, the rental of 1 rack of unused glasses is a cheap compared to the embarrassment of running out of glasses.