How it works
Drinks per drinking guest are the first-hour rate times the first hour (or the part of it if the event is shorter) plus the later-hour rate times the remaining hours. That is multiplied by the guests who will drink alcohol, increased by the safety buffer and rounded up. The total is divided across beer, wine and spirits by your percentages, with whole drinks allocated so the three add up to the total. Beer is counted as 12 oz servings and shown in cases of 24. Wine uses 750 ml bottles and your glass size, and spirits use your pour size and bottle size; whole servings per bottle are rounded down and bottles are rounded up.
Worked example
For 80 guests over 4 hours, all drinking, at 2 drinks in the first hour and 1 per later hour, each guest has 5 drinks, or 400 in all. With a 10% buffer that is 440. Split 40% beer, 30% wine and 30% spirits, that is 176 beers (8 cases of 24), 132 glasses of wine at 5 oz (27 bottles, 5 glasses each) and 132 spirit pours at 1.5 oz (9 bottles of 750 ml, 16 pours each).
Before you use the result
- The 2-then-1 rate is a common starting point, not a rule. Raise or lower it for your crowd, the time of day and whether food is served.
- The result covers alcohol only. Plan mixers, ice, water and non-alcoholic drinks separately.
- Round up if you can return unopened bottles and round down if you cannot. Follow local alcohol-service laws and serve responsibly.