There are two things that can quietly ruin a party: running out of drinks, and buying so much you're left with a garage full of warm White Claw. Neither is a great outcome. After bartending hundreds of events across Central Florida, I've developed a straightforward system for calculating exactly what you need — no guesswork, no waste.
The short answer is that most events average about one drink per guest per hour. But that rule gets nuanced fast depending on what you're serving, how long the event runs, and what kind of crowd you're dealing with. Let me walk you through it.
Start with the Drink-Per-Hour Rule
The industry standard is one drink per person per hour. For a four-hour event with 100 guests, that's 400 total drinks. That's your baseline. From there, you adjust based on three factors: bar type, crowd vibe, and time of day.
A morning brunch with mimosas and a relaxed crowd will come in below that average. A Saturday night open bar with a dance floor? Plan closer to 1.25–1.5 drinks per person per hour for the first few hours, then it typically tapers off as the night goes on. Get the baseline right and the adjustments are easy.
The Numbers by Guest Count
Here's the math broken down so you don't have to do it yourself. These numbers reflect a 4-hour event with an average drink rate — adjust the totals up or down for shorter or longer events.
| Guests | Total Drinks (4 hrs) | Beer (cases) | Wine (bottles) | Spirits (750ml) |
|---|---|---|---|---|
| 25 | 100 | 2 | 4 | 3–4 |
| 50 | 200 | 4 | 8 | 6–8 |
| 75 | 300 | 6 | 12 | 9–12 |
| 100 | 400 | 8 | 16 | 12–16 |
| 150 | 600 | 12 | 24 | 18–24 |
| 200 | 800 | 16 | 32 | 24–32 |
Pro tip: Always add a 15% buffer to your total. Drinks get knocked over, poured too heavy, or guests show up late and drink faster trying to catch up. The buffer is insurance, not excess — and whatever's left makes a great gift to the host.
Beer vs. Wine vs. Spirits — How to Split It
If you're running a full open bar, not every bottle of spirits equals the same number of drinks. Here's how to think about each category:
- Beer: One 24-pack case = 24 drinks. Most guests at a mixed-crowd event will drink 1–2 beers before switching to cocktails or wine.
- Wine: One 750ml bottle = approximately 5 glasses. Red tends to outsell white at evening events; white and rosé do better at daytime and outdoor events.
- Spirits: One 750ml bottle = approximately 17 standard 1.5oz shots. Vodka is almost always your highest-volume spirit, followed by tequila, then whiskey.
For a typical full open bar crowd, I recommend splitting roughly like this: 30% beer, 30% wine, 40% spirits (including mixers). Shift that ratio based on your crowd — a younger corporate crowd might lean heavier on beer, while a wedding reception usually skews toward wine and cocktails.
Adjust for Crowd Vibe
This is the variable most people underestimate. A group of 80-year-old relatives at a family reunion drinks very differently from a group of 35-year-olds at an office party. Here's a rough adjustment guide:
- Light drinkers (family events, daytime, seniors): subtract 20% from your baseline
- Average drinkers (mixed crowd, casual celebration): use the baseline as-is
- Heavy drinkers (bachelorette parties, late-night events, dance floors): add 25–30% to your baseline
Don't Forget Ice and Mixers
Most people calculate the alcohol perfectly and completely forget everything else. For a full open bar serving 100 guests over 4 hours, you'll need roughly:
- Ice: 1.5 lbs per person = ~150 lbs (this sounds like a lot until you're out at hour two)
- Cups/glasses: 2–2.5 per person to account for spills and people setting their drink down
- Mixers: 2 liters of soda water, juice, or tonic per 750ml of spirits is a safe ratio
- Garnishes: Limes, lemons, mint — a flat rate of $30–50 worth covers most full open bar setups at 100 guests
Skip the Math Entirely
If you'd rather not do any of this manually, I built a free alcohol calculator specifically for this. You plug in your guest count, bar type, event duration, and crowd vibe — and it spits out a complete shopping list broken down by category. It takes about 60 seconds and gets emailed to you automatically.
The calculator uses the same formula I use when I'm planning a client's event. It's not a guess — it's a tested system built on years of events across Central Florida.
And if you'd rather just hand the whole thing off? That's what WinterBrooke Bar is for. We plan, source (if needed), set up, serve, and clean up — so you actually enjoy your own event instead of counting bottles at 9pm.