About Party Quantities

Party Quantities is a small, independent collection of quantity calculators for anyone hosting a gathering — from a pizza night to a wedding. It's run by Diwakar Patel, who built it after watching one too many parties run out of ice while sitting on three spare bottles of gin.

Where the numbers come from

The formulas here aren't invented. They're the standard planning constants used across the catering and events industry: the two-drinks-first-hour rule, the five-glasses-per-bottle pour, the 3-2-1 spritz ratio (per the IBA and Aperol's own published recipe), the 60 g-per-litre coffee golden ratio, USDA-consistent meat yield ranges, and the 3/8 pizza rule. Each tool page states its formula and constants openly so you can check — or challenge — the working.

How the calculators are checked

Every calculator is tested against hand-worked examples before publication (the worked examples shown on each guide page are the actual test cases), and quantities always round up to purchasable units, because the cost of leftovers is lower than the cost of running out.

What this site is not

It's not medical, legal or safety advice, and it doesn't encourage drinking — a third of the quantities logic here exists specifically so non-drinking guests are catered for properly. Please drink responsibly and follow your local laws on serving alcohol.

Corrections

If a number here disagrees with your real-world experience, that's worth hearing about — quantity rules only stay good if they keep meeting actual parties. Contact us with what you served, to how many, and what ran out or was left over.