Running out of drinks halfway through the night is every host’s nightmare — and over-buying wastes money. So how much alcohol do you actually need for a party? After 20+ years behind the bar at Houston events, here’s the rule of thumb we use, plus a free tool to do the math for you.
Don’t want to do the math yourself? Our Houston mobile bar team plans quantities, shopping lists and service for you.
The bartender’s rule of thumb
Plan for about two drinks per guest in the first hour, then one drink per guest for every hour after that. For a 100-guest, four-hour event, that’s roughly 425 drinks. It sounds like a lot, but it accounts for the natural rhythm of a party — heavier at the start, tapering as the night goes on.
Turning drinks into bottles
Once you know your total drink count, you can break it down by type:
- Beer & seltzer: one can or bottle per drink. A standard case holds 24.
- Wine: a 750ml bottle pours about five glasses.
- Spirits: a 750ml bottle makes roughly 16 cocktails at 1.5 oz each.
Then split your total across those categories based on your crowd. A good default is 40% beer, 30% wine, and 30% cocktails — but a cocktail-forward celebration will lean more toward spirits.
Don’t forget the extras
Alcohol is only half the bar. You’ll also want ice (about 1.5 lbs per guest), mixers and sodas, plenty of bottled water, cups, napkins, and garnishes like limes and lemons. And always plan non-alcoholic options for the guests who aren’t drinking.
Let the calculator do the math
Rather than work it out by hand, use our free event drink calculator. Enter your guest count, event length, and drink mix, and it returns a full shopping list — beer by the case, wine and spirits by the bottle, plus ice, mixers, and more. It’s the fastest way to buy the right amount the first time.
Or let us handle it
When you book J Martini, we build your shopping list for you and pour it flawlessly on the day — flair bartending, custom cocktails, and full-service staff for your Houston event. Have a question first? Check our FAQ page or call (832) 756-1129 for a free quote.
Planning a specific event? See our Houston wedding bartenders and our corporate event bar service in Houston.
