You Actually Can’t Form Healthy Habits in 21 Days. Here’s How Long It Takes.

At some point, someone probably told you that it only takes 21 days to form a new habit. But none of us ever bothered to check the science on that. It just sounds right.

21 days is a very specific number of days. Science had to have determined that specific amount of time at some point, right?

Maybe. However, new research from the University of South Australia says that 21 days is a gross underestimation of how long it takes to form a habit. This was one of those studies of studies that took data from 20 different experiments that involved over 2,500 participants, mashed them all together, and then analyzed the data.

It Takes A Lot More Than 21 Days To Form A New Habit

The studies covered a range of habits people tried to develop—from wanting to floss more regularly to drinking more water daily and exercising more often. And all tried to do their new habits so often that the thought of doing them became nearly automatic. The researchers quickly found that firmly establishing a habit takes much longer than 21 days.

So, how long does it take to form a new habit? On average, it takes a person between 106 and 154 days to form a habit. The median time was between 59 and 66 days. And for some, it can take up to 335 days to firmly establish a habit.

That means if you want to turn exercising into something you automatically do without even thinking about it, some of you are going to have to think about doing it (and then actually do it) pretty damn often. And for the majority of the year.

Habit formation cannot be easily surmised in a pithy one-sentence bit of folk wisdom. Like most things in life, habit formation is filled with nuances and complexities that can vary wildly from person to person. It may take one person 50 days and may take someone else 130. The “why” can depend on factors like whether you can even fit that activity into your day given your schedule. And even whether or not you like the activity when you ultimately start doing it.

The only thing even closely related to a shortcut that the study’s lead author, Ben Singh, suggests is adding the new habit to your regular morning routine. That’s the time of day when, according to Singh, “the data shows you’re more likely to achieve it.”

You hear that? That means if you want to really stick to your new habit of smoking a pack of cigarettes every day, you’d better get started bright and early.