The standard planning number is one drink per guest per hour of open bar. It is not exact for every guest, some drink more, some drink none, but averaged across a full guest list it holds up consistently.
Breaking it down by phase
- Cocktail hour: plan for 2 drinks per guest in that first hour. Everyone arrives and orders close together, so demand spikes early.
- Reception: 1 drink per guest per hour after that, tapering slightly as the night goes on and dancing takes over from drinking.
- Total for a 5-hour open bar: 4 to 6 drinks per guest is the standard range planners quote.
Why rounding up matters more than rounding down
Running short on a batch mid-reception is a visible problem. Guests notice, and it is hard to fix quickly once the party is moving. Having leftover batch cocktails is a non-issue, since most bases hold well in the fridge for a few days. Round up.
Sizing the order
Colorway's 5-gallon batch serves roughly 120 drinks, which comfortably covers a wedding of 100 to 150 guests planning for cocktail hour plus a few hours of reception, when paired with wine and beer options alongside the batch cocktail.