How Long Does It Take to Form a Habit

The answer used to be “21 days!” And it came from a plastic surgeon.

In 1925, Dr. Maxwell Maltz began his practice in facial reconstruction, Over time, he noticed something very peculiar.

When he performed an operation such as a nose job, many of these patients could not see a difference…for around 21 days.  Similarly, when a patient had an arm or a leg amputated, the patient would sense a phantom limb for about 21 days before adjusting to the new situation.

He then wrote “These, and many other commonly observed phenomena tend to show that it requires a minimum of about 21 days for an old mental image to dissolve and a new one to jell.” In 1960, he published Psycho-Cybernetics, which went on to sell more than 30 million copies.

And that’s when the problem started

In the decades that followed, Maltz’s work influenced nearly every major “self-help” professional from Zig Ziglar to Brian Tracy to Tony Robbins. And as more people recited Maltz’s story — like a very long game of “Telephone” — people began to forget that he said “a minimum of 21 days” and shortened it to: “It takes 21 days to form a new habit.”

And that’s how society started spreading the common myth that it takes 21 days to form a new habit. It’s remarkable how often these timelines are quoted as statistical facts.

So what’s the real answer? How long does it actually take to form a new habit? Is there any science to back this up? And what does all of this mean for you and me?


How Long it Really Takes to Build a New Habit

Phillippa Lally is a health psychology researcher at University College London. In a study[ii] published in the European Journal of Social Psychology, Lally and her research team examined the habits of 96 people over a 12-week period. Each person chose one new habit for the 12 weeks and reported each day on whether or not they did the behavior and how automatic the behavior felt.

Some people chose simple habits like “drinking a bottle of water with lunch.” Others chose more difficult tasks like “running for 15 minutes before dinner.” At the end of the 12 weeks, the researchers analyzed the data to determine how long it took each person to go from starting a new behavior to automatically doing it.

So what IS the answer?

On average, it takes more than two months before a new behavior becomes automatic — 66 days to be exact. And how long it takes a new habit to form can vary widely depending on the behavior, the person, and the circumstances.

In Lally’s study, it took anywhere from 18 days to 254 days for people to form a new habit. In other words, if you want to set your expectations appropriately, the truth is that it will probably take you anywhere from two months to eight months to build a new behavior into your life — not 21 days.

 Finding Inspiration in the Long Road

Before you let this dishearten you, let’s talk about four reasons why this research is actually inspiring.

First, the researchers also found that “missing one opportunity to perform the behavior did not materially affect the habit formation process.” In other words, it doesn’t matter if you mess up every now and then. Building better habits is not an all-or-nothing process!

Second, there is no reason to get down on yourself if you try something for a few weeks and it doesn’t become a habit. It’s supposed to take longer than that! There is no need to judge yourself if you can’t master a behavior in 21 short days.

Third, you don’t have to be perfect. Making a mistake once or twice has no measurable impact on your long-term habits. This is why you should treat failure like a scientist, give yourself permission to make mistakes, and develop strategies for getting back on track quickly.

And fourth, embracing longer timelines can help us realize that habits are a process and not an event.

Understanding this from the beginning makes it easier to manage your expectations and commit to making small, incremental improvements — rather than pressuring yourself into thinking that you have to do it all at once.

                                                                                    Where to Go From Here
At the end of the day, how long it takes to form a habit doesn’t really matter.

Whether it takes 50 days or 500 days, the only way to get to Day 500 is to start with Day 1.

So forget about the number, enjoy the process, and enjoy the fact that your brain is rewiring itself…RIGHT NOW!