Cocktail Party Bottle Calculator

Running out of alcohol at a cocktail party 90 minutes before the end is a small social disaster. Buying twice as much as you need is wasteful and expensive. The math for getting it right is simple.

total_drinks = guests × hours × drinks_per_hour_per_person

Industry standard for a hosted bar:

• First hour of party: 2 drinks per person
• Each hour after the first: 1 drink per person
• Wedding receptions (4-5 hours): 4-6 drinks per person on average
• Casual dinner party: 1-2 drinks per person per hour, calmer pace

So a 4-hour party for 30 people: first hour 60 drinks, plus 90 drinks across the other three hours, total about 150 drinks. The rule of thumb most catering guides use is “1 drink per person per hour” averaged across the night — which gets you to 120, low by about 25 percent.

Splitting the total. A typical mixed crowd splits roughly 50% liquor cocktails, 30% wine, 20% beer. A heavily wine-drinking crowd flips it. Add 10 percent for spillage, ice loss, and the friend who orders a complicated cocktail you’ve never made and bins it after one sip.

Bottle yields:

• 750 mL spirit bottle: 17 standard 1.5 oz pours
• 1.75 L spirit bottle: 39 pours
• 750 mL wine bottle: 5 standard 5 oz pours
• 12 oz beer bottle: 1 drink
• Champagne 750 mL: 6 standard flutes (4 oz)

For our 4-hour party of 30 with 150 drinks: 75 cocktails, 45 wine pours, 30 beers. That is roughly 4-5 750 mL spirit bottles (or two handles), 9 bottles of wine, and a 30-pack of beer. Pick two spirit bases (vodka and gin, for example) and have one mixer for each (tonic, soda, juice). Two wine choices (a chardonnay and a pinot noir) are plenty.

Mixers and ice. Tonic and soda water at about 4 oz per cocktail means roughly 1 liter of mixer per 8 drinks. Ice is the thing nobody buys enough of: plan 1 lb of ice per guest for chilling cans and bottles, plus another 1 lb per guest for cocktails. So 30 guests means roughly 60 lbs of ice. Most homes have one ice maker that produces 2-3 lbs per hour. Buy bagged ice the day of, period.

Last detail. State liquor laws aside, most retailers will let you return unopened bottles for a refund or store credit, especially before a major holiday. Buy slightly more than you think you need, and return what you don’t use. That is almost always cheaper than running out and Uber-ing to a 24-hour liquor store at 11 PM.