To determine how much wine you should order for a party, you will need to figure in a few things. First how many people will be drinking, how long will they be drinking, and what kind of party is this? A normal bottle of wine will provide roughly about 5 glasses of wine. At a normal cocktail party, a person should drink about 2 glasses of wine. If you know guests will drink more/less you can use the 5 glasses of wine per bottle to get a rough estimate on how many bottles you should order.