When it comes to social gatherings, there's nothing more embarrassing than not having enough of food and drink to serve. Toasts tend to be the highlight of special events. If you're in charge of ordering wine for a toast, you need to know how much wine equals one serving, and how many servings are in an average bottle of wine.
What to Buy
Since one wine serving is about 5 ounces, and a standard bottle holds approximately 25 ounces, you need about eight bottles of wine -- but buy nine to be on the safe side -- for a 40-person toast. So you don't portion out too much wine per glass, line up all 40 glasses on a table. Measure 5 ounces into one glass and use it as a guide to eyeball the right amount to pour in each glass. Consider buying boxes of wine, which may contain roughly 100 ounces depending on the brand, if you wish to serve your guests refills.