• New research found that, unlike many people think, there is no real timeframe connected to forming a new habit.
• According to experts, the amount of time it takes to form a new habit largely depends on what the habit is, and the circumstances surrounding the habit (like environmental factors).
• Experts recommend keeping track of progress, developing a social support system, and practicing patience and self-compassion while forming a new habit.

No, it doesn’t take 21 days to form a new habit.

New research, published earlier this year in the Proceedings of the National Academy of Sciences (PNAS) found that there is no set timeframe associated with habit forming.

While it is commonly believed that it takes three weeks (21 days) to create a habit, the timeframe may differ, depending on a variety of factors.

“You may have heard that it takes about 21 days to form a habit, but that estimate was not based on any science,” Colin Camerer, PhD, study author and behavioral economist at The California Institute of Technology, said in a news release.

“Our work supports the idea that the speed of habit formation differs according to the behavior in question and a variety of other factors.”

Here’s how timeframes to create habits may differ, and recommendations from experts on how to sustain new behaviors.

There Is No One-Size-Fits-All Timeframe for Habit Formation 

To determine how long it would generally take for people to form a habit, Camerer and colleagues used machine learning tools and objective large data sets of thousands of people.

They specifically collected information on over 30,000 people who went to the gym and 3,000 hospital workers who washed their hands during hospital shifts. Afterward, they used machine learning to determine the time it took for those behaviors to become habitual. 

The research team found that, on average, it could take up to a full six months to establish a new exercise routine. But for hospital workers who were washing their hands while on-shift, it only took weeks to create a habit.

That said, they concluded that there is no one-size-fits-all timeframe for habit-building.

“There is no magic number for habit formation,” Anastasia Buyalskaya, PhD, study co-author and now an assistant professor of marketing at HEC Paris, said in a news release.

Rather, the study found that the timeframe to build a habit depends on the individual, the kind of habit they’re trying to form, and their environment. 

But even with these considerations—which can certainly elongate the time needed to form a habit—individuals can hypothetically form new habits very quickly, Ernesto Lira de la Rosa, PhD, psychologist and Hope for Depression Research Foundation Media Advisor, told Health. 

“It can take up to 1 month to form a new habit but this requires consistently engaging in the behavior throughout the entire time frame,” he said. “Some people are able to form a habit in less than 1 month and others may need up to 3 or 6 months to build a new habit.” 

Several factors come into play when it comes to a person’s ability to establish and maintain a new habit, Nicholas Crimarco, PhD, psychologist at NewYork-Presbyterian/Columbia University Irving Medical Center, told Health.

Some of the key factors include how difficult the new behavior or habit is and how rewarding the habit might be, he explained.

For instance, if a habit is more challenging, it may require higher levels of motivation and consistency. If the new habit is too difficult, people may struggle to stay committed over time.

Furthermore, if the habit is not associated with a reward, it can be hard for a person to stay motivated or engage in the habit consistently.

Crimarco added that environmental factors such as social support might also impact a person’s ability to engage in a new behavior. If a person does not have a strong support system from their friends and family, it can hinder their habit-building process. 

Personal motivation is also a critical factor in building and maintaining new habits. Lira de la Rosa explained that motivation can be internal or external, but internal motivation is often needed to establish a new habit.

“That is because we have invested energy in this new habit and this motivation lasts longer than external motivation, such as forming a new habit to please someone else,” he said. 

Another factor that can affect habit formation is consistency, Aimee Keith, PsyD, Eating Recovery Center, and Pathlight Mood & Anxiety Center Clinical Manager, told Health. 

“Habits and all learning behaviors are impacted by consistency,” she said. “The more consistent I am with a habit, the faster it will form. The more inconsistent, the weaker the behavior will be.”

Understanding and addressing these factors can allow individuals to set realistic goals, develop strategies to overcome potential challenges, and increase the chances of long-term consistency and success. 

"It is imperative to think about the ease of the new habit, the way you learn best, and making sure you are considering any potential setbacks,” Lira de la Rosa said. 

Common Mistakes in Habit-Building

According to experts, common mistakes people make when forming a new habit include:

• Setting unrealistic goals: Starting with smaller, achievable goals can help you sustain new habits gradually
• Choosing a habit that doesn’t align with a core value: To stick with a habit, it should align with your personal values
• Rushing a habit: Instead of setting yourself up for failure with a difficult timeline, focus on small, slow steps to form a sustainable habit
• Aiming for perfection: Planning for mistakes and setbacks will keep your focus on the new habit and less on failure
• Being too critical: Practice positive self-talk to encourage growth as you form new habits

How To Build and Sustain New Habits 

There are a variety of strategies for forming a new habit. Here are ways experts suggest you go about forming a habit successfully:

Determine If Your Habits Are Realistic and Important

According to Keith, one way to form a new habit and maintain it is to decide if the habit you are trying to build is realistic and how important the habit is to you.

For example, if your goal is to build a habit of meditating daily, consider starting with a 5-minute practice, especially if you have a busy schedule. Reflect on why this habit is important to you, whether because it may help manage stress, improve sleep, or enhance focus. 

Track Your Progress

It can be very helpful to monitor your progress visually so that you can see it over time, Crimarco explained.

This way it becomes more reinforced as you see your progress.

“Research has demonstrated that tracking your progress is one of the most helpful ways to change your behavior over time,” he said.

For example, if your goal is to increase the number of steps you take daily, use mobile apps to record your steps. Seeing a visual representation of your progress can encourage you to consistently walk every day. 

Develop a Social Support System

It can also be helpful to find and build a social support system.

“Social support systems are useful for keeping individuals accountable and for helping the process of behavior change feel more rewarding,” Crimarco said.

It’s worth considering reaching out to others who are also trying to form new habits to have accountability partners as you work towards a new goal.

Have Patience and Self-Compassion

It’s also important to be patient with yourself and have self-compassion while forming a new habit, Lira de la Rosa explained.

“Taking on a new habit is positive and it is okay if you treat yourself with kindness during this time,” he said.

For example, if you miss a day of your exercise routine, practice self-compassion by understanding that setbacks are a natural part of the habit-building process. Take that time to adjust your plan, and continue to move forward with a positive and understanding mindset.