How much to buy, for any gathering

Free calculators that turn a guest count into an exact shopping list — drinks, food and ice, with nothing to sign up for.

Every calculator on this site answers the same question: you know how many people are coming — what exactly do you buy? Each tool uses the standard quantity rules that caterers and event bartenders work from, shows its math, and rounds up to whole bottles, bags and boxes, because running out at 9pm is worse than having spares.

Drink calculators

Food & supplies calculators

Planning guides

Why the math is the same everywhere

Nearly every quantity rule on this site descends from a handful of catering constants: guests drink about two drinks in the first hour and one per hour after; a 750 ml wine bottle pours five glasses; a spirits bottle pours about 17 shots; an adult eats three slices of a large pizza or about half a pound of cooked meat; a party consumes roughly one pound of ice per guest per hour in warm weather. The calculators combine those constants with your guest count and round everything up to what you can actually buy. Each tool page explains its own formula, so you can check the working — or argue with it.