If you want to make friends as an adult, budget more than 200 hours per person. That is the threshold for a close friend, according to research from the University of Kansas.

Here is the puzzle. A full-time job, by the Australian Bureau of Statistics definition, means at least 35 hours a week. At that rate you clock 200 hours beside the people at the next desk in under six weeks. Yet adults in the same research reported spending hundreds of hours with colleagues and still called them acquaintances.

I put it down to design. School did the design work for us. Most workplaces quietly undo it, so the hours we spend there buy very little friendship.

Time together counts only when it is the right kind.

What it takes to make a friend

Jeffrey Hall is a professor of communication studies at the University of Kansas. In 2018 he published the first study to count the hours it takes to make a friend, in the Journal of Social and Personal Relationships.

He ran two studies. The first surveyed 355 adults who had moved to a new place in the previous six months and were looking for friends there. The second followed 112 first-year students through their first nine weeks at the university.

Both studies pointed to the same thresholds. Roughly 50 hours together turns an acquaintance into a casual friend. Around 90 hours makes a friend. A close friend takes more than 200. People who stayed acquaintances had usually spent 30 hours or less together.

The type of time matters as much as the amount. Hall found that joking around, catching up and meaningful conversation all speed friendship along. Hours spent working together count for less.

Sociologists had already described why. Rebecca G. Adams is a sociology professor at the University of North Carolina at Greensboro. She told the New York Times in 2012 that close friendship rests on three conditions. Condition one is proximity, meaning you are physically near each other. Condition two is repeated, unplanned interaction, meaning you keep running into each other by chance. Condition three is a setting where people let their guard down and confide in each other.

Adams said this explains why so many people meet their lifelong friends at college. A campus supplies all three conditions every day, for years.

Hall's student data shows how much time campus life hands out. When two people move up a friendship stage, he found, they double or triple their time together within three weeks. Some first-year students spent a third of their waking hours in a month with one good friend. Few jobs leave room for that.

Why the office hours count for so little

Work supplies the first condition in full. Your colleagues sit metres away, five days a week.

The second condition arrives in a planned form. Meetings run to an agenda and a calendar invite. The chance encounters in the kitchen and the corridor are the minutes an efficiency drive cuts first.

The third condition is where work falls short. A colleague may one day review your performance, compete for your promotion or manage your team. People keep their guard up around anyone with a say in their pay. That is a sensible instinct, and it holds the relationship at acquaintance level.

Hall described the difference to Psychology Today. A casual friend who asks "What's been going on in your life?" is inviting your life into the relationship. Compare that with walking into the office and saying hey. Here is why that matters: the office supplies the hours and strips out the talk that turns hours into friendship.

Remote and hybrid work have cut into the hours as well. Hybrid workers split their week between home and the office. Gallup, the US research firm, tracked how many hybrid workers have a best friend at work. The share fell from 22% in 2019 to 17% in 2022, as Fortune reported.

The cost shows up at home too. Ending Loneliness Together is an Australian network of organisations working on loneliness. Its 2023 State of the Nation report found at least 1 in 3 Australians feel lonely. 1 in 6 feel very lonely at any given time. Hall's and Gallup's research comes from the United States. Reading it across to Australian workplaces is my own inference, though an office works the same way in Melbourne as in Kansas.

A monthly lunch and one good question

Gallup links having a best friend at work to profitability, safety and staff retention. It also found that workers sometimes need permission from their leaders before they build close friendships on the job. That permission is yours to give, and the three conditions show you where to spend it.

Protect the unplanned minutes. Adams's second condition is chance contact. Keep one shared lunch time, one coffee machine and one break area that everyone uses. Leave the gaps between meetings empty on purpose, because those gaps are where repeated, unplanned interaction happens.

Hold a regular monthly lunch. Hall's advice to anyone who works beside a potential friend is to switch the context: go to lunch or out for a drink. Make it the same lunch every month, away from the desk, with the talk kept to life. Work stays at the office. Adams's conditions reward repetition, so a lunch that returns every month does the work one big Christmas party cannot.

Ask the real question first. Managers set the tone for the third condition. Open each one-on-one by asking what has been going on in the person's life, and listen to the answer. Keep performance talk for its own meeting, so the catch-up stays a safe place to speak.

Book the lunch. Ask the question. Repeat it next month.