Wine per Person Calculator

How the Wine per Person Calculator Works

Buying wine for a party is a guessing game until you do the math. This calculator turns four simple inputs — number of guests, event length in hours, glasses per guest per hour, and glasses per bottle — into the number of bottles (and cases) you should buy. It uses the classic event-planning rule of roughly one glass per guest per hour, but you can adjust every figure for your crowd.

The Formula

First work out total glasses, then convert glasses into whole bottles:

Total glasses = guests × hours × glasses per guest per hour Bottles = round up (total glasses ÷ glasses per bottle)

A standard 750 ml bottle pours about five 150 ml glasses, so that is the default. Bottles are always rounded up to a whole number because you cannot buy a fraction of a bottle, and cases assume 12 bottles per case.

Worked Example

For 20 guests at a 4-hour event, drinking 1 glass per hour, with 5 glasses per bottle:

• Total glasses = 20 × 4 × 1 = 80 glasses
• Bottles = round up (80 ÷ 5) = 16 bottles
• Cases = round up (16 ÷ 12) = 2 cases

Quick Wine Planning Reference

Guests	Hours	Glasses/hr	Bottles needed
10	3	1	6
20	4	1	16
50	4	1	40
100	5	1	100

Tips for Getting It Right

• Use about one glass per guest per hour as a starting point, then nudge it up for a celebratory crowd or down if you also serve beer and spirits.
• Assume not everyone drinks wine — if half your guests prefer other drinks, halve the glasses-per-hour figure.
• Round up to whole cases so you are never short, and remember unopened bottles often store or return well.
• Split between red, white and sparkling based on the season and menu; a common starting mix is roughly equal red and white.

This is a planning estimate. Real consumption varies with the occasion, the time of day and your guests, so always build in a small buffer rather than ordering the bare minimum.