Party Alcohol Calculator

Enter your guest count and how long the party runs, and you get a shopping list: cases of beer, bottles of wine, bottles of spirits, and whether a keg makes sense. It is not a ratio and not a hedge, because you cannot carry a ratio into a store.

Guests (everyone who will be in the room, including the ones who never drink)

Hours the party runs (door open to last call, not the length of the invitation)

What kind of event (this sets the default split across beer, wine and spirits, which you can override below)

Are you serving spirits?

Yes, full bar No, beer and wine only

Share of guests who will not be drinking (%, optional) (only for people you know will not touch a drink. Blank assumes everyone drinks, which is the direction that buys enough)

Beer share (%) (blank uses the default)

Wine share (%) (blank uses the default)

Add up what it costs?

No Yes

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Data reviewed: August 2026. Figures here come from published sources and change over time. How we verify

How much alcohol for a party, in bottles rather than ratios

Every page you have already read gave you a ratio. One drink per person per hour, half of it wine, add ten percent, good luck. That is not an answer you can carry into a store. This one hands back a list: this many cases, this many bottles, this many kegs, and what each container gives you when you open it.

Three things do the work. The first is the rate people actually drink at, which is not flat. The second is the split across beer, wine and spirits, which every source states as fact while disagreeing with every other source. The third is container arithmetic, which is the only genuinely exact part of the whole exercise and which almost nobody shows you.

We also do the rounding in public. Everything you buy rounds up, because you cannot buy two thirds of a bottle and because the two failure modes are not the same size: running out ends a party at ten o'clock, and an unopened bottle keeps until Christmas. Everything a container gives you rounds down, because a bottle that holds 16.9 shots pours 16 drinks somebody can actually hold. Those two rules point in opposite directions on purpose, and both of them point at having enough.

The formula

drinks per drinking guest = 2 in the first hour + 1 an hour to hour 4 + 0.75 an hour after that
total drinks = drinking guests × drinks per guest, rounded UP
beer, wine and spirits drinks = total × your split, each rounded UP
cases of beer = beer drinks ÷ 24, rounded UP
bottles of wine = wine drinks ÷ 5, rounded UP
bottles of spirits = spirit drinks ÷ 16, rounded UP
container yields = fluid ounces in the container ÷ the pour, rounded DOWN

One drink means the same thing in all three columns: a 12 oz beer at 5 percent, a 5 oz glass of wine at 12 percent, and a 1.5 oz shot at 40 percent. Multiply each of those out and you get 0.6 fl oz of pure alcohol every time, which is the US standard drink. That is not a coincidence, it is the definition, and it is why a guest who moves from beer to wine has changed nothing but the glass. Our BAC calculator uses exactly the same figures, and a test compares the two files so they cannot drift apart.

The container arithmetic, which is the exact part

A US fluid ounce is 29.5735295625 mL by definition, so a 750 mL bottle holds 25.36 fl oz. Everything below is one division away from that, and none of it is quoted from anybody.

750 mL ÷ 5 oz pour = 5.07 glasses of wine, so 5 glasses
750 mL ÷ 1.5 oz pour = 16.91 shots, so 16 drinks
1.75 L ÷ 1.5 oz pour = 39.45 shots, so 39 drinks
a case = 24 cans of 12 oz
half barrel = 15.5 gal × 128 ÷ 12 = 165.3, so 165 beers
quarter barrel = 7.75 gal, so 82 beers
sixth barrel = 5.17 gal, so 55 beers

Keg sizes look like arbitrary trade jargon and are not. A US beer barrel is 31 gallons by federal definition, so a half barrel is 15.5 gallons, a quarter is 7.75 and a sixth is a shade over 5.16. Divide by 12 ounces and you have the pour counts above. Anybody quoting you 165, 82 and 55 got them the same way.

Now the part worth your attention. You will see a 750 mL bottle described as 17 shots, as 16 drinks, and as 14 drinks, all in print, all this year. Every one of those is defensible and none of them is a mistake about the bottle. Seventeen is 16.91 rounded the friendly way. Sixteen is the honest count of full 1.5 oz pours. Fourteen is a 1.75 oz pour, which is what a lot of wedding bars actually serve. The bottle never changed. The pour did. When a page gives you a number without telling you the pour, it has hidden the only variable that mattered, and rounding 16.91 up to 17 is how a shopping list quietly comes up one drink short per bottle, which over ten bottles is a round of drinks nobody has.

Worked example

50 guests, a four hour casual party, full bar.

Four hours at our rate is 2 drinks in the first hour and 1 an hour after, which is 5 drinks per guest, so 250 drinks. The flat one-per-hour rule would have said 200, and the 50 drink gap is the first hour it never counted.

The casual party default split is 50 percent beer, 30 percent wine, 20 percent spirits, which is 125 beers, 75 glasses of wine and 50 mixed drinks. Turned into things you can put in a cart, that is 6 cases of beer, 15 bottles of wine and 4 bottles of spirits. Or in one sentence, which is the version worth remembering: fifty people for four hours is six cases, fifteen bottles and four bottles.

Rounding up to whole containers already gave you 33 spare drinks: 19 beers, 0 glasses of wine and 14 shots. That is your buffer, and it is a real number rather than the vague "add ten percent" every other page offers. Notice the wine landed exactly on 15 bottles with nothing to spare, which is the one line in this order worth padding by hand.

Beer at 125 cans is enough for the keg question. A single half barrel pours 165, which covers it with 40 to spare and one tap. Two quarter barrels would save exactly one beer of waste and cost you a second tap and a second deposit, so it is not worth it. The catch that decides it for most people: the 6 unopened cases can go back to the store on Monday, and a tapped keg cannot.

The 50 mixed drinks need 9 to 12 litres of mixers, call it 6 two litre bottles across tonic, soda and juice, plus about 5 lb of limes and lemons. That is the line people remember at six o'clock on the day.

Why the first hour is worth two drinks

The rule the trade actually uses is two drinks per guest in the first hour and one an hour after that. It is not a fudge factor. Guests arrive with nothing to do, nobody to talk to yet and no food out, and the one socially available activity is holding a glass. Then they find people, the food comes out, and the pace halves.

Most calculators use a flat one drink per hour, and the shortfall is exactly one drink per guest, which for fifty people is fifty drinks and for two hundred is two hundred. It always lands in the first ninety minutes, which is the worst possible time to run to the store.

The other end of the curve is ours, and we will label it clearly because it is the one adjustment on this page that reduces what you buy. After hour four we drop to three quarters of a drink an hour. People slow down once there is food, the early leavers have gone, and a ten hour event is not ten hours of hour one. That is our estimate, not a published rule, and it means our curve and the flat one-per-hour rule cross at exactly eight hours. Below eight hours the flat rule under-buys you. Above eight hours it over-buys. If you would rather ignore our tail entirely, take the flat number for a long event and you will simply have more left over, which is the mistake nobody minds making.

The split nobody agrees on

Here is a thing worth knowing before you trust any page on this subject, including ours. Three well-known sources publish three incompatible splits for the same job. One says half your drinks will be wine. Another says half will be spirits. A third puts beer at 40 percent. All three are stated with equal confidence, and all three are perfectly reasonable, because the honest truth is that none of them has met your friends.

So on this page the split is a field, not a fact. The event type sets a default, the defaults are printed in your result every time, and three boxes let you overwrite them. Our defaults are ours, built from where the published ranges overlap:

Event	Beer	Wine	Spirits
Casual party or backyard	50%	30%	20%
Wedding reception	30%	50%	20%
Cocktail party	20%	30%	50%
Holiday or office party	30%	40%	30%

One cross-check that made us happier about the wedding row. Turn spirits off at a wedding and the remaining shares scale to 62.5 percent wine and 37.5 percent beer. The commonly published figure for a beer and wine only reception is 60/40. We did not aim at that, it fell out of the arithmetic, and two independent routes landing two and a half points apart is about as much validation as this subject allows.

What actually moves the split is your crowd, and you know things about them that no calculator does. An outdoor summer afternoon runs beer-heavy. A seated dinner runs wine-heavy. A room of people in their twenties will empty the spirits and leave the wine, and a room of people in their sixties will do the reverse. Move the boxes. The whole point of putting them there is that your guess about your own friends beats our average.

The field that costs people money: who is not drinking

Gallup put the share of US adults who drink alcohol at 54 percent in July 2025, with 44 percent describing themselves as total abstainers, the lowest drinking rate in the ninety years it has run the survey. That is a real and genuinely useful fact about the country, and it is also the number that wrecks a shopping list when it is used wrong.

Here is the trap. The one to two drinks an hour rate is a rate per drinking guest. If you then knock 44 percent off your headcount because that is the national abstention rate, you have discounted the same thing twice and you will be short by nearly half. Some calculators do exactly this, quietly.

Use the non-drinker field only for people you specifically know: the friends who never drink, the guests who are pregnant, the ones driving an hour home, a work party where a third of the room is under 21. Leave it blank otherwise. Blank assumes everybody drinks, which is the wrong assumption in the safe direction.

What is not on this list, and what to do about it

Ice. The rule of thumb is one to one and a half pounds per guest, and it is deliberately not on your shopping list, because ice is bought the morning of, it depends on how many coolers you own, and it is the one item where a week of planning is worthless. Buy more than you think. Everyone always says that and everyone is always right.

Glassware. Count on more glasses than guests, because people set them down and lose them within the hour, and a party that runs out of glasses looks exactly like a party that ran out of drinks. Two per guest is the usual guidance for anything with a bar.

The non-alcoholic half of the bar. This is not a courtesy line. Somewhere between a tenth and a third of your room is not drinking, and the difference between a good party and an awkward one is whether the interesting thing to hold is alcoholic. Sparkling water, good soda, something with a lime in it. Plan roughly one non-alcoholic drink per guest per hour and you will not be caught out.

Corkscrews and bottle openers. One is never enough. Two is barely enough.

Serving alcohol to people you like

The arithmetic above is the whole job of this page, and this section is not a lecture. It is the practical part that hosts who have done this a few times all do the same way.

Put the food out early and keep it out. Food genuinely slows the pace, and it also gives people something to do with their hands, which is half of what the first-hour spike is really about. Keep something good that is not alcoholic within arm's reach of the bar rather than in a fridge in another room, because proximity decides what people pick up.

Know before the night starts how anyone who should not drive is getting home. That is a plan made at six o'clock, not a negotiation at midnight, and it works far better when it was arranged before anybody had a reason to argue about it.

If a guest is trying to work out where they stand, our BAC calculator is next door. It gives a range rather than a single number, it headlines the high end on purpose, and it will not tell anybody they are fine to drive, because no calculator can do that. The page that tells you how much to buy should point at the page that tells you what it does, and the pages share their drink figures exactly so they cannot contradict each other.

Buying it, and the honest bit about kegs

A keg is cheaper per beer and it is a commitment. A half barrel holds 165 twelve ounce pours, which is nearly seven cases, and once it is tapped it is yours. Cans you never open go back to the store on Monday in most states, and that return policy is usually worth more than any case discount, so ask about it before you ask about the discount.

Where a keg wins outright is a long outdoor party with one style of beer and a confident headcount. Where it loses is anything where the crowd might be half the size you expected, or where people want three different things. Our recommendation mixes sizes when mixing them wastes less, which is what a rental company would actually deliver: a full keg plus a sixtel beats two full kegs on waste and beats four sixtels on taps, and each extra keg is another tap, another deposit and another thing to load back into a car.

Two practical notes that catch first-timers. A keg needs to be cold for hours before it pours properly, which means a tub and a lot of ice, and it needs a tap you almost certainly do not own. And a keg deposit is refundable, so the sticker price on the shelf is not the number you are actually spending.

On wine, twelve bottles is a case and most stores discount by the case, so if your order lands at ten or eleven bottles it is often cheaper to buy twelve. On spirits, a 1.75 L handle is 39 drinks against 16 in a 750, so two and a half fifths in one bottle, usually at a better price per drink. If a spirit will get used again, buy the handle. If it is one cocktail for one night, buy the fifth.

Sources

Where the numbers on this page come from. We go to the body that publishes the figure, not to another calculator. Figures on this page were checked against these sources in August 2026. See how we verify.

Party Planning Guide, Weaver's Liquor Store. REPORTED, and the closest thing to a primary source this subject has, because it is a store telling you what to buy rather than a blog telling you what to think. Figures used: two drinks in the first hour and one an hour thereafter; a 1.5 oz pour as the standard drink of spirits; a 750 mL bottle giving 16 drinks and a 1.75 L bottle giving 39; a 750 mL bottle of wine giving 5 glasses at a 5 oz pour; and beer planned at about 12 oz per guest per half hour to hour. Note that the 16 and the 39 are exactly what the container arithmetic gives when yields are rounded DOWN, which is the direction this page rounds them and the direction most competing pages do not.
Party Planning: A Drink Calculator for Weddings, Graduations, and More, Haskell's. REPORTED, the second source for the tapering rate, and the source of one of the corrections on this page. It states the rule plainly: two drinks per person for the first hour of the party, then one drink per hour thereafter, with the formula (guests x 2) + (guests x hours after the first). It also publishes a 50/25/25 split of wine, beer and spirits. Where we part company: it puts a 750 mL bottle at 17 shots of 1.5 oz. The bottle holds 25.36 fl oz, which is 16.91 shots, so 17 is a yield rounded up. We use 16, because a yield rounded up is how a shopping list comes up short, and the same page's own wine figure of 5 glasses from 5.07 rounds the other way.
This Wedding Alcohol Calculator Will Solve Your Wine-and-Spirit Woes, The Knot. REPORTED, and included specifically because it disagrees with the two sources above in two useful ways. First, its split is 50 percent liquor, 25 percent beer and 25 percent wine, which is the mirror image of Haskell's 50 percent wine. That disagreement is why the split on this page is an input with a labeled default rather than a hidden assumption. Second, it puts a 750 mL bottle of liquor at 14 drinks and a 1 L bottle at 19, both at a 1.75 oz pour, which is a heavier pour than the 1.5 oz standard. Both figures reproduce exactly from the container arithmetic at that pour, so the industry's famous disagreement about how many drinks are in a bottle is really a disagreement about the pour, and this page says so. It also uses a flat one drink per guest per hour with no first-hour bump.
U.S. Drinking Rate at New Low as Alcohol Concerns Surge, Gallup. MEASURED. As of July 2025, 54 percent of US adults say they drink alcohol and 44 percent describe themselves as total abstainers, the lowest drinking rate in the 90 years Gallup has asked. Used on this page as context for the non-drinker field and never as a default, because the consumption rate above is a rate per DRINKING guest: applying a national abstention figure on top of it discounts the same thing twice and sends a host home short. The survey also reports drinkers averaging 2.8 drinks a week, which is a reminder that a party is not an average week.
Guide to Beer Keg Sizes and Dimensions, KegWorks. REPORTED, used only to confirm the trade names and nominal volumes: half barrel 15.5 gallons, quarter barrel 7.75, sixth barrel about 5.16. The serving counts on this page are not taken from here or anywhere else. A US beer barrel is 31 gallons by federal definition, so the three sizes are exact fractions of it, and dividing by a 12 oz pour gives 165, 82 and 55. Our test suite derives all three from 31 gallons rather than quoting them, which is the difference between a figure we can defend and a figure we copied.
Mixer Math: How To Calculate Alcohol Needs for a Party, The Kitchn. REPORTED, the source of the two mixer rules this page prints side by side: 6 to 8 fl oz of tonic, soda or juice per mixed drink, and the older rule of one quart of mixers for every three guests. The two disagree, and which one is more generous depends on how spirits-heavy your split is, so the page shows both and names which is larger for your event rather than picking one silently. Also the source of the citrus figure, 2 to 3 pounds per 30 guests, where we use the top of the band, and of the ice rule of thumb of 1 to 1.5 pounds per guest, which we quote in the content and deliberately keep off the shopping list.
Alcohol Facts and Statistics: What is a standard drink?, National Institute on Alcohol Abuse and Alcoholism. MEASURED, and the definition that makes the three columns on this page comparable. A US standard drink contains 14 grams of pure alcohol, which is 0.6 fl oz. A 12 oz beer at 5 percent, a 5 oz glass of wine at 12 percent and a 1.5 oz shot at 40 percent each work out to exactly 0.6 fl oz of ethanol, which is why this page can add beers, glasses and cocktails together and call the total drinks. These are the same constants the BAC calculator uses, and our test suite evaluates that file and compares them with strict equality so the two pages cannot drift apart.

Frequently asked questions

How much alcohol do I need for 50 guests?

For a four hour casual party with a full bar, 50 guests works out at 250 drinks: 6 cases of beer, 15 bottles of wine and 4 bottles of spirits. That is built on two drinks per guest in the first hour and one an hour after, then split 50 percent beer, 30 percent wine and 20 percent spirits. Stretch the same 50 guests to six hours and the drink count goes to 325.

How many drinks per person for a 4 hour party?

Five, not four. The rule the trade uses is two drinks in the first hour and one an hour after that, because guests arrive thirsty and with nothing to do but hold a glass. A flat one drink per hour is the most common shortcut and it under-buys you by exactly one drink per guest, which for 100 people is 100 drinks and always lands in the first ninety minutes.

How many drinks are in a 750 mL bottle?

It depends entirely on the pour, which is why you will see three different answers in print. A 750 mL bottle holds 25.36 fl oz. At a 1.5 oz pour that is 16.91, so 16 full drinks. At the 1.75 oz pour many wedding bars use it is 14. Poured as wine at 5 oz it is 5.07, so 5 glasses. Anyone quoting 17 shots has rounded 16.91 up, which is the wrong direction for a shopping list.

How many beers are in a keg?

A half barrel pours 165 twelve ounce beers, a quarter barrel 82 and a sixth barrel 55. Those are not trade lore, they are arithmetic: a US beer barrel is 31 gallons by federal definition, so the three sizes are 15.5, 7.75 and about 5.16 gallons, and 15.5 gallons is 1,984 fluid ounces, which is 165.3 twelve ounce pours.

Is a keg cheaper than cans for a party?

Per beer, usually yes. As a decision, it depends on how sure you are about the crowd. A tapped keg is yours whether or not anyone drinks it, and unopened cases can go back to most stores on Monday, so the return policy is often worth more than the case discount. A keg also needs a tap you probably do not own and hours in a tub of ice to pour properly, and the deposit is refundable, so the shelf price is not what you are actually spending.

What percentage of guests drink beer versus wine versus liquor?

Nobody knows, and the confident answers disagree. One well-known guide puts wine at 50 percent of drinks, another puts spirits at 50 percent, and a third puts beer at 40 percent. That is why this calculator makes the split an input with a default per event type instead of hiding it: casual parties lean beer, weddings lean wine, cocktail parties lean spirits. You know your friends better than any average does, so move the numbers.

Should I buy less alcohol if some guests do not drink?

Only for people you specifically know will not drink. The one to two drinks an hour rate is already a rate per drinking guest, so subtracting a general abstention rate on top of it discounts the same thing twice. Gallup put the share of US adults who drink at 54 percent in July 2025, but that is a national figure and not your guest list. Leave the field blank unless you can name the people.

How much extra alcohol should I buy as a buffer?

Usually none, because rounding up to whole containers has already given you one. For 50 guests over four hours the order carries 33 spare drinks purely from rounding, and this calculator prints that number instead of adding a vague ten percent on top of it. The exception is a headcount that is a guess rather than a list of names: for that, run the numbers again with a quarter more guests and buy against the bigger answer.