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How Much Spirits for a 20 Guest Graduation Party?

You will need approx.

🥃
5
bottles of spirits

For a 20-guest graduation party lasting 4 hours

info 15% buffer included
66
Total servings
3.3
Per person
+1
Buffer bottles

How We Calculated This

Our bartender-tested formula, step by step

1

Estimate actual drinkers

20 guests × 80% drinking rate
= 16 drinkers

At small events, about 80% of guests typically drink alcohol.

2

Calculate base consumption

16 drinkers × 1.5 drinks/hour × 4 hours
= 96 base drinks

Industry standard is 1.5 drinks per person per hour for a 4-hour event.

3

Apply consumption decay

Adjusted for drinking slowdown over time (decay factor: 3.25)
= 78 adjusted drinks

People drink faster in the first hour and slow down as the event progresses.

4

Apply graduation party modifier

× 0.85 (-15% for spirits)
= 66 spirits servings needed

Graduation Partys typically consume 15% less spirits than average.

5

Convert to bottles

66 servings ÷ 17 servings per bottle
= 3.9 bottles (raw)

Each bottle of spirits provides 17 servings.

6

Add 15% buffer & round up

3.9 × 1.15 = 4.5, rounded up
= 5 bottles

Always round up and add a buffer. Running out is worse than having leftovers!

Why trust this formula?

Based on industry standards and refined by bartenders with 30+ years of experience. We factor in consumption decay (people drink less as events progress) and real-world drinking percentages.

📊 Quick Reference: Spirits by Guest Count

Guests Spirits Needed Total Servings
25 guests 7 bottles 83 servings
50 guests 13 bottles 165 servings
75 guests 19 bottles 248 servings
100 guests 25 bottles 330 servings
150 guests 38 bottles 495 servings
200 guests 50 bottles 660 servings

* All calculations include a 15% buffer. Amounts for graduation party.

The Essentials

🥃 5 bottles Spirits
22 liters Mixers (soda, tonic, juice) (Variety is key)
32 lbs Ice (~2 lbs per person)
32 glasses Cocktail glasses (2 per drinker) Buy
9 pieces Garnishes (limes, lemons)

The Host's Secret

Editorial Curation

ATMOSPHERE

"Set up a visible '21+ only' bar area and a killer mocktail station so younger guests feel included."

Pro Tip #1
PREPARATION

"Parents of graduates drink about 30% less than the graduate's friends - plan your ratios accordingly."

Pro Tip #2
TIMING

"Keep champagne cold but corked until group photo time - pop bottles for the shot!"

Pro Tip #3
SERVICE

"Outdoor graduations in summer need extra cold drinks and 2x the ice you think you need."

Pro Tip #4
PRESENTATION

"Mix of generations means variety is key - have options for every age group."

Pro Tip #5
🛒

Buying Guide

Graduation parties typically skew toward beer and lighter drinks. Stock up on popular light beers and have a good selection of non-alcoholic options since many guests will be under 21. Sparkling cider is a great champagne alternative for toasts that includes everyone.

🎉

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