What this calculator does
Get a drinks shopping list for your party. Running out halfway through is awkward, and a garage full of leftover cases is expensive. Enter your guest count and how long the party runs. You'll see how many drinks to plan for in total. You'll also see what that means in cans of beer, bottles of wine and spirits, and bottles of mixer. Cans of soft drinks and the ice are on the list too.
It uses a rule of thumb that hosts and caterers rely on. Guests have about two drinks in the first hour and one in each hour after that. You choose how the drinks split between beer, wine, mixed drinks and non-alcoholic options. Then you add a safety margin. Every line is rounded up, so you're more likely to have a little left over than to run short.
Where it's used
Why this math matters outside the classroom:
- Backyard party. A host expecting 30 guests for 3 hours plans 2 + 1 + 1 = 4 drinks each, which is 120 drinks before any margin.
- Wedding reception. A couple splitting 400 drinks as 35% wine buys 140 glasses, or 28 bottles at 5 glasses per bottle.
- Percent of a total. Students find 40% of 275 drinks as 0.40 × 275, which is 110 cans of beer.
- Office celebration. An office manager orders 2 L bottles of mixer: 24 mixed drinks at 4 fl oz each need about 2.8 L, so 2 bottles.
- Club fundraiser. Volunteers rounding up 41.25 mixed drinks to 42 learn why planners always round shopping quantities up.
Grade level and standards: Grade 6; Common Core State Standards for Mathematics 6.RP.A.3.c, 6.RP.A.3.b. © Copyright 2010. National Governors Association Center for Best Practices and Council of Chief State School Officers. All rights reserved.
How to use it
- Enter the number of guests and how many hours the event runs.
- Set the share of drinks you expect to be beer, wine and mixed drinks. Whatever is left over goes to soft drinks.
- Choose a safety margin. 10% is a sensible default. Raise it for a long celebration or a crowd you know drinks more.
- Read the shopping list: cans of beer (and 24-packs), 750 mL bottles of wine and spirits, 2 L bottles of mixer, cans of soft drinks and pounds of ice.
What the inputs mean
- Event length
- Part hours count in proportion. So a 2.5-hour event counts 2 drinks for the first hour, plus 1.5 for the rest.
- Share that is beer
- Think about your guests rather than a formula. A backyard barbecue may be mostly beer, and a dinner mostly wine. If some guests don't drink alcohol, put their share under soft drinks.
- Share that is mixed drinks (spirits)
- Whatever share is left becomes soft drinks. That means soda, sparkling water, juice and other non-alcoholic drinks by the can or glass. Water for the table is extra.
- Extra for safety
- The margin is added to the total before it's split. So every kind of drink grows by the same share.
Formula and method
drinks per guest = 2 + 1 × (hours − 1) total drinks = guests × drinks per guest × (1 + margin ÷ 100), rounded up drinks of each type = total × share, rounded up wine bottles = glasses ÷ 5 (a 750 mL bottle pours five 5 fl oz glasses) spirit bottles = mixed drinks ÷ 16 (sixteen 1.5 fl oz pours per 750 mL) mixer = 4 fl oz per mixed drink, in 2 L bottles; ice = 1 lb per guest
Hours is how long the party runs, and margin is your safety extra in percent. Share is the percent of drinks you set for each type. The two-then-one pace matches how people drink at a party: more when they arrive, then about one an hour.
Multiply by the number of guests and add the margin to get the total drinks. The calculator then shares that total out by type. Finally, it turns each type into the cans and bottles you actually buy.
A 750 mL bottle holds about 25.4 US fl oz (fluid ounces). That's 5.07 glasses of wine at 5 fl oz, or 16.9 pours of spirits at 1.5 fl oz. Only whole glasses and pours count. So the calculator uses 5 and 16 per bottle, leaving a little spare in each bottle. A beer or soft drink is one 12 fl oz can or bottle.
Worked example
You are hosting 50 guests for 4 hours, expecting 40% beer, 30% wine and 15% mixed drinks (leaving 15% soft drinks), with a 10% margin.
- Per guest: 2 + 1 × 3 = 5 drinks. For 50 guests: 250 drinks. With the margin: 250 × 1.1 = 275 drinks.
- Beer: 40% of 275 = 110 cans, about 5 cases of 24.
- Wine: 30% of 275 = 82.5, rounded up to 83 glasses; 83 ÷ 5 = 16.6, so 17 bottles.
- Mixed drinks: 15% of 275 = 41.25, rounded up to 42; 42 ÷ 16 = 2.6, so 3 bottles of spirits, and 42 × 4 fl oz is about 5.0 L of mixer, or 3 bottles of 2 L.
- Soft drinks: 42 cans. Ice: 50 lb.
Result: Plan on 275 drinks: 110 beers, 17 bottles of wine, 3 bottles of spirits with 3 bottles of mixer, 42 soft drinks and 50 lb of ice.
Understanding the result
The total is a planning figure, not a target. Most hosts would rather have a few unopened bottles than run dry. That's why every line rounds up.
Unopened beer, wine and spirits keep well. So buying extra costs little if you'll use them later. Some shops also take back unopened bottles. Ask before you buy.
Assumptions and limitations
- Guests drink about 2 drinks in the first hour and 1 in each hour after.
- A wine pour is 5 fl oz. A spirit pour is 1.5 fl oz with 4 fl oz of mixer. Beer and soft drinks come in 12 fl oz cans.
- Ice is 1 lb per guest for glasses. Chilling bottles in tubs needs more.
- Drinking habits vary a lot by crowd, time of day, weather and whether food is served. Adjust the shares and margin to suit your party.
- It doesn't plan for a toast. A sparkling wine toast needs about one bottle per 6 to 8 guests. It also doesn't cover cocktails with several spirits, or punch bowls.
- It's a quantity planner, not advice about alcohol. Make sure guests have safe ways to get home. Serve plenty of water and food, too.
Frequently asked questions
How many drinks per person should I plan for a party?
A common rule is two drinks per guest in the first hour, and one per hour after that. For a 4-hour party, that's 5 drinks per guest before any margin. Plan lower for a daytime or family event.
How many glasses of wine are in a bottle?
A standard 750 mL bottle holds about 25 fl oz. That's five 5 fl oz glasses, with a splash to spare. Larger pours of 6 fl oz give about four glasses.
How much ice do I need for a party?
About 1 lb per guest covers ice in drinks. If you also chill bottles and cans in tubs or coolers, buy extra. A full cooler can easily take 10 to 20 lb on its own.
Can I use this for a wedding?
Yes. Enter the reception length and the drink mix you expect. Weddings often lean toward wine and add a sparkling toast. Add the toast on top of the list.
How this calculator is checked
Method: Host and caterer rule of thumb (2 drinks per guest in the first hour, 1 per hour after, the same pace used by the party food calculator); standard pours of 5 US fl oz wine and 1.5 US fl oz spirits; exact US fluid ounce (29.5735295625 mL). The calculation is covered by automated tests with known reference values and edge cases. Last updated 2026-10-18. Found a problem? Tell us.
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