About this tool
The Party Alcohol Calculator is a free, in-browser tool that estimates how much beer, wine, and liquor to buy for an event so you neither run dry nor drown in leftovers. Enter your guest count, how many hours the party runs, the share of guests who don't drink, and how you expect drinks to split between beer, wine, and spirits. It returns whole units to buy — cans of beer (and cases), 750 mL wine bottles, and 750 mL liquor bottles — plus the total number of standard drinks. Everything runs locally in your browser, so nothing you enter is uploaded.
The method uses the classic caterer drinks-per-hour model: guests average about two drinks in the first hour and one drink for each additional hour, so drinks per person = hours + 1. Total drinks = drinking guests × (hours + 1), where drinking guests = total guests × (1 − non-drinker %). That total is split by your beer/wine/liquor percentages (which must sum to 100). Each category is then converted to containers: one beer drink = one 12 oz can, a 750 mL wine bottle pours about five 5 oz glasses, and a 750 mL liquor bottle yields about sixteen 1.5 oz shots. It also suggests roughly 1 liter of mixers per liquor bottle.
As a worked example, 30 guests with 10% non-drinkers over a 4-hour party gives 27 drinkers × 5 = 135 standard drinks. Split 50/25/25 that is about 68 beers (3 cases), 34 wine drinks → 7 bottles, and 34 liquor drinks → 3 bottles. Every category rounds up to whole units so you're covered. This is an estimate: heavy-drinking crowds, hot weather, or a signature cocktail can push consumption higher, so round up if in doubt.