How Much Alcohol Do You Need for a Party?

The simple formula

Every good drinks plan starts with one number: how many servings you'll pour. Here's the math we use in our party calculator:

1. Guests × hours × 1 drink. One serving per guest per hour is a common planning baseline. It's a stocking estimate, not a target — some guests will have less, a few will have more, and many will switch to water.
2. Add a 10% buffer. Running out mid-party is worse than having a few unopened bottles. Most sealed spirits keep for years, so leftovers aren't wasted.
3. Set aside about 25% for alcohol-free drinks. Designated drivers, guests who don't drink and anyone pacing themselves should have something better than soda.

For 50 guests over 4 hours: 50 × 4 × 1 = 200 servings, plus 10% = 220. Of those, about 55 are mocktails and 165 are cocktails.

Quick-reference table

Use this as a starting point, then plug your real menu into the calculator for an exact shopping list.

Planning estimates with a 10% buffer and 25% of drinks alcohol-free. Spirit bottles assume one 1.5 oz pour per cocktail. Scroll sideways on a phone to see every column.

Turning drinks into bottles

A standard 750 ml bottle holds about 25 oz. How many drinks that makes depends on the pour:

• Spirits: a standard 1.5 oz pour gives about 17 drinks per bottle. Many cocktails use 2 oz, which drops it to about 12 — that's why the calculator works from your actual recipes.
• Wine: a 5 oz glass gives about 5 glasses per bottle.
• Beer: one 12 oz can or bottle is one serving.
• Sparkling wine for a toast: a 3–4 oz pour stretches one bottle to 6–8 flutes.

These pour sizes match the U.S. “standard drink” definition: 1.5 oz of 80-proof spirits, 5 oz of wine or 12 oz of regular beer each contain about the same amount of alcohol.

Mixers, citrus and the things people forget

• Mixers: a highball is usually 3–4 oz of mixer to 1.5 oz of spirit, so mixers run out before liquor does. Buy more soda, tonic and ginger beer than you think.
• Citrus: one lime gives about 1 oz of juice; one lemon about 1½ oz. A margarita-heavy party can go through dozens. Squeeze juice up to a few hours ahead and keep it chilled.
• Garnishes: one lime cuts into about 8 wedges or 6 wheels.
• Water: put out pitchers of water from the start, and keep them full. It's the single most useful thing on any drinks table.
• Cups: plan on 2–3 glasses per guest — people put them down and forget them.

How much ice

Ice is the item hosts most often run out of. Our rule: 1 lb per guest for the first two hours, then ½ lb per guest for each extra hour, plus extra for frozen drinks and for chilling bottles and cans in a tub.

On a hot day or outdoors, add another 25–50%. Ice is cheap; running out isn't.

Keep the menu small

Two or three cocktails plus one great mocktail is plenty. A short menu means fewer bottles, less waste and a faster bar. Pick drinks that share ingredients — a Margarita and a Paloma both use tequila and lime, so one shopping trip covers both.

For bigger crowds, batch one drink in a punch bowl or pitcher so guests can serve themselves while you mix to order.

Host responsibly

• Serve food throughout the party, not just at the start.
• Make the alcohol-free options just as appealing as the cocktails.
• Measure pours with a jigger so drinks stay consistent.
• Line up rides or a place to stay, and never let a guest drive impaired.
• Only serve guests of legal drinking age, and stop serving anyone who's had enough.