Ah, it’s January, and we all know what that means: we’re all turning over new leaves, becoming gym bunnies, eating healthily, saving money instead of spending, reading eight books a week, and giving 10 percent of our income to charity. Or at least, that’s our intention – but it’s so hard to stay motivated, isn’t it? To remember to do it all, day after day?

Perhaps a better idea would be to take those virtuous behaviors and make them automatic – turn them into habits. But how do we do that? How long does it take? And, not to be pessimistic, but… what about when we fail?

How long does it take to form a habit?

You may have heard that it takes around 21 days to form a habit – it’s one of those “everybody knows” kind of factoids. And like so many such pieces of information, it doesn’t hold up to scrutiny: the myth “appears to have originated from anecdotal evidence about the adjustment period for plastic surgery,” explains University College London’s Science of Habits homepage, “but does not relate to habits as we know them.”

Instead – well, we’ve got bad news. In a 2010 study that followed nearly 100 people as they attempted to pick up a healthy habit, researchers found that it could take up to 254 days – that’s the length of time between January 1 and September 11 – for a new routine to stick.

Now, that doesn’t mean it’ll take you the whole eight-plus months to pick up a new routine – in fact, the average amount of time was found to be a lot less – just 66 days, or a little over nine weeks. That was how long it took participants to reach “95 percent automaticity”, specifically: the point at which they only had to consciously perform the action one out of 20 times.

And yeah, we know – nine or 10 weeks is still a long time. But there is an upside: that crazy variation in time period goes both ways, and one person in that same study managed to form a habit in just 18 days. That’s quicker even than the mythical “three weeks” figure – so what makes the difference?

“It takes 66 days […] on average to form a new habit after the first time the new action is performed, but this can vary from person to person and for different actions,” explains UCL. “Similarly, forming habits for simple behaviors (such as drinking a glass of water) was a lot quicker than for more complex behaviors (e.g. doing 50 sit-ups).” 

Take, for example, a 2023 study that followed millions of participants in their goals of picking up one of two habits – either to become a regular gym-goer, or to wash their hands regularly. Clearly, one of those aims is more complex and difficult than the other, and the results bore that out: “Contrary to the popular belief in a ‘magic number’ of days to develop a habit, we [found] that it typically takes months to form the habit of going to the gym but weeks to develop the habit of handwashing in the hospital,” the authors reported.

In other words: if you’re hoping to pick up a habit quickly, aim low – and you might just make it to automaticity within the month.

How to create a habit

So, you’ve chosen a habit to pick up. There’s not much you can do about who you are, but is there any way you can change your environment or routine to help yourself minimize the time until automaticity? In other words: is there a hack for habit formation?

In fact, there is. “To create a habit you need to repeat the behavior in the same situation,” explained Phillippa Lally, now a Senior Lecturer in Psychology at the University of Surrey, back in 2009. “It is important that something about the setting where you perform the behavior is consistent so that it can cue the behavior. If you choose a context cue, for example after lunch, we don’t think that it matters if you eat lunch at different times in the day.”

These cues can be anything, really – a specific time of day; an action; even a person. In fact, the weirder the better: according to one 2016 study, cues work better when they stand out from the rest of your day – so, maybe try linking your daily gym trip to a rousing rendition of “Physical” by Olivia Newton-John, behavioral scientists suggest, rather than hoping you’ll remember to go after your third cup of coffee each day.

Another key is to make a plan. “There are deep and robust literatures on the topic and on the related power of goals, goal setting, and mental simulation,” notes one 2015 paper on the subject. “The evidence clearly shows that plan making can increase follow-through.”

So, say your goal is to get into the habit of eating some fruit each day. Don’t just leave it there: go to the store; buy some apples. Put them in your bag and set an alarm; plan to eat them at a specific time. 

“Unpack[ing] the when, where, and how of fulfilling their intentions can increase [people’s] likelihoods of following through,” the paper explains. “In part that’s because making an action plan overcomes people’s tendency to procrastinate when they intend to behave in beneficial ways that fail to provide instant gratification as well as their tendency to be overly optimistic about the time it will take to accomplish a task.” 

That’s not all. Make a detailed plan of action, and you’re less likely to fail through simple forgetfulness – the culprit for up to 70 percent of missed goals, according to at least one study. Plus, you’ll be more likely to, well, feel bad if you fail: “committing to behaving in a certain way and then failing to follow through on this explicit commitment causes discomfort,” explains the paper. “Anticipating such discomfort probably contributes to why planning prompts increase follow-through.”

PS: want to really supercharge that discomfort? Tell someone else what you plan to do. Nothing motivates like peer pressure, after all.

Breaking a habit

Picking up a good behavior is one thing; shaking a bad one is quite another. Want to give up smoking for the new year, or finally quit sucking your thumb like a little baby? It’s possible – but we have bad news: “Breaking habits is very difficult,” Lally warned.

First of all, you have to really, really want to get rid of it. “It is difficult to break any habit even when you are motivated to do so,” Lally explained. “If you are ambivalent about breaking it then you will be less likely to succeed.”

Still, if you’re dead set on losing the routine, the same advice applies: control your environment so that it’s as easy as possible to not perform the behavior. Don’t keep your cigs on you, for example; if you’re trying to eat less sugar, then don’t hang out with that one friend who always sneaks you a KitKat. 

And, finally: if you screw up, don’t despair. Habit forming is a process, not an event – it helps, of course, to be consistent, but “missing one opportunity did not significantly impact the habit formation process,” Lally said.

However, “people who were very inconsistent in performing the behavior did not succeed in making habits,” she cautioned. “We do not yet know what level of consistency is necessary to form a habit.”