How much beer do I need for 100 guests?

You need 18 cases of beer for 100 guests at a birthday party. This provides 375 total servings with a 15% buffer to ensure you don't run out.

How much beer per person for a birthday party?

Plan for 3.8 servings of beer per person at a birthday party. This accounts for the fact that not everyone drinks alcohol and consumption naturally slows as the event progresses.

How many servings are in a case of beer?

One case of beer contains 24 servings. For 100 guests, you'll need 18 cases to provide 375 total servings.

What percentage of guests will drink beer at a birthday party?

At a birthday party with 100 guests, approximately 70 guests (70%) will actively drink. Our formula accounts for this when calculating the 18 cases you need.

Should I buy extra beer as a buffer?

Yes! Our calculation of 18 cases already includes a 15% buffer (2 extra cases). This ensures you won't run out even if some guests drink more than average. It's always better to have leftovers than to run short.

How long will 18 cases of beer last for 100 guests?

18 cases of beer will last approximately 4 hours for 100 guests at a birthday party. This calculation factors in the natural slowdown of consumption as the event progresses.

Calculate a different drink for this event

🍷 Wine 🍺 Beer viewing 🥂 Champagne 🥃 Spirits

How Much Beer for a 100 Guest Birthday Party?

🍺

cases of beer

For a 100-guest birthday party lasting 4 hours

15% buffer included

375

Total servings

3.8

Per person

Buffer cases

How We Calculated This

Our bartender-tested formula, step by step

Estimate actual drinkers

100 guests × 70% drinking rate

= 70 drinkers

At large events, about 70% of guests typically drink alcohol.

Calculate base consumption

70 drinkers × 1.5 drinks/hour × 4 hours

= 420 base drinks

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

Apply consumption decay

Adjusted for drinking slowdown over time (decay factor: 3.25)

= 341 adjusted drinks

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

Apply birthday party modifier

× 1.1 (+10% for beer)

= 375 beer servings needed

Birthday Partys typically consume 10% more beer than average.

Convert to cases

375 servings ÷ 24 servings per case

= 15.6 cases (raw)

Each case of beer provides 24 servings.

Add 15% buffer & round up

15.6 × 1.15 = 17.9, rounded up

= 18 cases

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: Beer by Guest Count

Guests	Beer Needed	Total Servings
25 guests	5 cases	94 servings
50 guests	9 cases	188 servings
75 guests	14 cases	281 servings
100 guests (you)	18 cases	375 servings
150 guests	27 cases	563 servings
200 guests	36 cases	750 servings

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

Your Shopping List

Everything you need, plus essentials you might forget

🍺

Beer

The main event

cases

Don't forget these

Ice (Keep those beers cold!)

216 lbs
Coolers (2 cases per cooler)

9 coolers
Buy

Email Your Shopping List

We'll send your complete list plus pro tips for a stress-free event

No spam, unsubscribe anytime

Pro Tips for Your Birthday Party

Insider advice from experienced bartenders

💡

Milestone birthdays (21st, 30th, 40th, 50th) consume 25% more than regular birthdays.

⏰

Birthday parties have 3x more shots than any other event type - stock shooters.

🎯

Consumption drops 60% during cake and presents - factor in 30-45 min of low drinking.

🧊

Know your crowd's age - 21-30 year olds drink 30% more beer, 50+ drink 35% more wine.

✨

Consider a signature 'birthday cocktail' to make the guest of honor feel special.

🛒 Buying Guide

Birthday parties vary wildly by age group. For 21-35, stock up on beer and mixers for cocktails. For 40+, increase your wine selection. Always have extra for milestone birthdays - people celebrate harder at 30, 40, and 50.

Explore More Calculators

Find the perfect amounts for any event

More for your Birthday Party

Different guest count?

Other events (100 guests)

🎉

Planning a different event?

Use our free calculator for any combination of drinks, events, and guest counts.

Browse All 336 Calculators