How the drink calculator works
There’s no exact way to know what guests will drink, so wedding and party planners use simple rules of thumb. This calculator applies the common ones, shows its working, and lets you change every assumption.
- Drinks per guest. Either about 1 drink per guest per hour [1][2][5], or the front-loaded version: 2 drinks in the first hour and 1 per hour after that [3][4]. The Knot notes people drink more early in an event and slow down later [1].
- Guests who drink. Only guests who drink alcohol count toward beer, wine and spirits. Everyone else can be planned for with non-alcoholic drinks at the same pace.
- Time of day. For a brunch or lunch event, The Knot suggests about 15% fewer drinks [1].
- Mix. Total drinks are split by your mix. Zola suggests 50% wine, 30% spirits and 20% beer for a full bar, or 75% wine and 25% beer for beer and wine only [2]. The Knot suggests 50% spirits, 25% beer and 25% wine [1]. Your crowd matters more than either.
- Extra margin. A buffer on top so you don’t run out. Unopened bottles can often be kept or returned, so check your store’s policy.
drinks = guests who drink × drinks per guest × (1 + margin) bottles = drinks in that category ÷ servings per bottle, rounded up
Servings per bottle, case and keg
Servings come from container size divided by pour size, rounded down to whole pours. Default pours are the US standard drink sizes: 12 oz of beer, 5 oz of wine and 1.5 oz of spirits [8].
| Container | Servings | Sources |
|---|---|---|
| 750 mL wine at 5 oz | 5 | [1][2][4][5] |
| 750 mL spirits at 1.5 oz | 16 | [4] |
| 1 L spirits at 1.5 oz | 22 | [4][5] |
| 750 mL sparkling, toast pour | 6 (about 4 oz) or 8 (about 3 oz) | [1][2] |
| Half barrel keg, 15.5 gal | 165 × 12 oz | [6][2] |
| Quarter barrel (pony) keg, 7.75 gal | 82 × 12 oz | [6] |
| Sixth barrel keg, 5.16 gal | 55 × 12 oz | [6] |
Kegs lose some beer to foam, especially when they’re first tapped, so a small margin helps.
Ice and mixers
Ice: an ice maker’s guide suggests 1–2 lb per guest, toward the top of that range when ice also chills bottles and food [7]. Hot weather and outdoor events need more.
Mixers: about 1 liter of soda, tonic or juice for every 12 mixed drinks, based on Williams Sonoma’s figure of mixer for about 12 highballs per liter [5]. Juice-heavy cocktails need more.
Planning notes
- Have water and non-alcoholic choices available all event long.
- If your venue or caterer pours, ask for their own estimate; their pours and pricing may differ.
- If you’re buying in bulk, check whether your retailer accepts returns of unopened bottles.
- Think about how guests will get home, and follow your venue’s rules and local laws on serving alcohol.
Common questions
How much alcohol do I need for 100 guests?
For a 5-hour evening wedding where everyone drinks, at 2 drinks in the first hour and 1 per hour after, that’s about 600 drinks, or 660 with a 10% margin. With a 50/30/20 wine/spirits/beer mix, that’s roughly 66 bottles of wine, 13 bottles (750 mL) of spirits and 6 cases of beer. Adjust the numbers above for your guests.
How many bottles of wine do I need for a wedding?
Divide the wine drinks by 5, since a 750 mL bottle pours five 5 oz glasses [1][2]. At 300 glasses of wine, you need 60 bottles, or 5 cases.
How many kegs do I need?
A half barrel pours about 165 twelve-ounce beers [6][2]. If 150 guests drink 1 beer an hour for 4 hours and beer is 20% of drinks, that’s 120 beers: one half barrel.
How much sparkling wine for a toast?
About 1 bottle per 8 guests for a small toast pour, or 1 per 6 for a fuller glass [2][1]. Many guests toast with what they’re already drinking, so you can buy less if you prefer [1].
How much ice per guest?
About 1 lb per guest for drinks, or 2 lb if ice also keeps bottles and food cold [7].
Sources
- The Knot, “Wedding Alcohol Calculator: How Much to Buy for Your Wedding”About 1 drink per guest per hour, more early on; 50/25/25 spirits/beer/wine mix; 15% fewer for brunch or lunch; 5 glasses per bottle of wine, 6 of sparkling
- Zola, “How to Calculate Alcohol Needs for Your Wedding”1 drink per guest per hour; 50/30/20 and 75/25 mixes; 5 glasses per wine bottle; 165 servings per 15.5 gal keg; 8 toast pours per bottle
- Tasting Table, “The Clever Way To Determine How Many Drinks You’ll Need For A Party” (2023)2 drinks per guest in the first hour, then 1 per hour
- Spec’s Wines, Spirits & Finer Foods, “Party Planning”2 drinks in the first hour, then 1 per hour; 5 servings per 750 mL of wine; 16 drinks per 750 mL and 22 per liter of spirits at 1.5 oz
- Williams Sonoma, “Drink Calculator for Cocktail Parties”About 1 drink per guest per hour; 5 glasses of wine per 750 mL; 1 L of mixer for about 12 highballs
- Toast, “How Many Beers Are in a Keg? Your Guide to Keg Sizes”Keg volumes: half 15.5 gal (~165 × 12 oz), quarter 7.75 gal (~82), sixth 5.16 gal (~55)
- Reddy Ice, “Ice Calculator”1–2 lb of ice per person, more when ice also chills drinks and food
- NIAAA, “What Is A Standard Drink?”Standard serving sizes: 12 oz beer, 5 oz wine, 1.5 oz spirits