An equation that tells you exactly when to arrive at a party to not be weird. What a ridiculous idea! Why, the only people who would use that are those who break out in a cold sweat wondering if they’ll be socially ostracized for being late, or awkwardly gawked at for being the first ones there. People who’ll map the location in advance to find the closest Starbucks so that they have a place to retreat too if no one else is there. People who will write a bulletin about it for an “economics” website so that they can easily find it in the unlikely scenario that someone invites them to a Halloween event.

*Ahem*. Walt Hickey wrote:

• The chaps at FiveThirtyEight organized a crowd sourced experiment to figure out when people show up to parties.
• They found that the median individual shows up to a party 58 minutes after it was meant to begin.
• But it depends on the size of the party. In those that have fewer than 23 attendees, the median guest is only 29 minutes late.
• Those with more than 25, the median person comes 70 minutes into the event.
• As a general rule of thumb, if you want to be the median guest to arrive, show up 42 minutes late, allowing for an additional 4 minutes for every ten members attending.

Read the caveats about the data, the 9% of people who arrive before a party begins, and see some excellent graphs and visualizations, as well as additional trends here.

Source: FiveThirtyEight