What this estimate does and does not do
This calculator estimates bar stock for private events such as parties, weddings, receptions, and small hospitality events. It converts a drink-count estimate into practical order units: beer cases, wine bottles, spirit bottles, mixer bottles, and ice bags.
It is not a responsible-service plan, liquor licence guide, bartender staffing plan, or legal compliance tool. Alcohol laws, venue rules, guest age, insurance, transport, and bartender requirements vary by location. Always follow local alcohol laws, venue policies, and responsible service guidance.
Formula used
The calculator starts with total drink demand:
drinking guests = guest count × drinking guest %
drinks per drinker = first-hour drinks + (event hours - 1) × later-hour drinks
base drinks = drinking guests × drinks per drinker
total drinks = base drinks × (1 + buffer %)Then it splits the total across beer, wine, and spirits:
beer servings = total drinks × beer share
wine servings = total drinks × wine share
spirit servings = total drinks × spirits share
beer cases = ceil(beer servings / beers per case)
wine bottles = ceil(wine servings / servings per wine bottle)
spirit bottles = ceil(spirit servings / servings per spirit bottle)Mixer and ice estimates are then layered on top:
mixer litres = spirit servings × mixer oz per drink / 33.814
mixer bottles = ceil(mixer litres / mixer bottle litres)
ice lb = guest count × ice lb per guest
ice bags = ceil(ice lb / ice bag size)Worked example
For 100 guests, 85% drinking guests, a 4-hour event, 2 drinks in the first hour, 1 drink each hour after, and a 15% buffer:
drinking guests = 100 × 85% = 85
drinks per drinker = 2 + 3 × 1 = 5
base drinks = 85 × 5 = 425
total drinks = 425 × 1.15 = 488.75 ≈ 489 drinksWith a 35% beer, 45% wine, 20% spirits mix:
beer ≈ 171 servings = ceil(171 / 24) = 8 cases
wine ≈ 220 servings = ceil(220 / 5) = 44 bottles
spirits ≈ 98 servings = ceil(98 / 17) = 6 bottlesHow to use the result
- Adjust drinking guest percentage for age mix, daytime events, transport, and culture.
- Adjust first-hour and later-hour rates for heavy or light drinking crowds.
- Use the category split to match your crowd, not a generic formula.
- Buy extra only where returns are allowed or leftovers are useful.
- Keep water and soft drinks separate from the alcohol estimate.
- Confirm bartender, glassware, garnish, ice, and cooler needs before ordering.
Assumptions and limitations
- Beer is treated as one serving per bottle/can.
- Wine is treated as a 750 ml bottle with 5 servings by default.
- Spirits are treated as 750 ml bottles with 17 servings by default.
- The mixer calculation is only for spirit drinks, not soda/water for all guests.
- Drink consumption is not truly linear; guests often drink more early and taper later.
- Weather, dancing, dinner service, transport, and crowd habits can change consumption significantly.
Frequently asked questions
How do you estimate drinks for an event?
Start with drinking guests, event hours, and drinks per guest. A common event rule is around 1 drink per guest per hour, or 2 drinks in the first hour and 1 each hour after.
How many glasses are in a wine bottle?
A standard 750 ml wine bottle is commonly planned as about 5 glasses at a 5 oz pour. Actual pours can vary by venue and glassware.
How many cocktails are in a 750 ml liquor bottle?
A 750 ml bottle has about 25.4 fluid ounces. At a 1.5 oz pour, that is roughly 16–17 standard spirit servings.
How much ice should I buy for an event?
For drinks and coolers, many planners use about 1 to 1.5 lb per guest as a starting point. Hot outdoor events, long service, and food-on-ice need more.
Should I include non-drinkers in the alcohol estimate?
It is better to use a drinking-guest percentage. Count adults who are likely to drink alcohol, then plan separate water and soft drinks for everyone.