About Party Sums

Party Sums is a set of free calculators for the quantity questions behind a party or wedding: how much to buy for the bar, how much food to order, how much ice, how big a tent or dance floor, how big a cake, and how a budget splits across vendors. Each one shows the rule it uses and a table, so the answer can be checked, or remembered for the next event.

The conventions

Drinks follow the bartender's rule of two per guest in the first hour and one an hour after, converted to bottles at five glasses per 750 ml of wine, sixteen cocktails per 750 ml of spirits and six flutes per bottle of sparkling. Food uses the caterer's buffet plate: six ounces of protein, four of each side, two of greens, with children counted as half an adult. Ice is a pound per guest, more outdoors. Tents use square feet per seat by seating style plus fixed zones for the bar, buffet, band and dance floor. Dance floors assume half the room dancing at once at four and a half square feet each. Cake servings come from Wilton's serving chart for round and square tiers and from slice geometry for sheets. The wedding budget uses the percentage split most planners publish.

What this site doesn't do

It doesn't store what you enter, require an account, or know your guests. A crowd of college friends drinks more than one of grandparents; a venue may cap capacity below what the square-footage rule allows; alcohol service is governed by local law and your venue's licence. Treat every number as the average planners start from and adjust for the people you actually invited.

Corrections

If a rule, convention or table here is wrong, email hello@partysums.com. The maths is stated on each page so a correction can be checked against it.