Our awesome alcohol calculator will determine your needs! It determines how many bottles of wine, beer, and liquor you will need based on your specific guests.Ready to buy booze for your wedding? We have a wedding alcohol calculator as well as detailed advice on how to figure out what you need. The easiest way to calculate the cost is that usually the budget for an open bar is between 10 to 20 percent of the overall budget for the wedding. Here's a basic formula: Total Alcohol Needed = (Average Drinks per Guest) × (Number of Guests) × (Duration of Event in hours) × (Percentage of Alcohol Content) Wondering how much alcohol you will need for your next event? Use this calculator to get the total cost of your wedding. Enter the information that is essential for your wedding. From toasts to cocktails, this tool ensures your guests stay refreshed without overspending or running out.