How long does it take to break a habit?

A habit is a link in memory between a cue and an action: dinner ends, the phone comes out. The link is learned slowly, through repetition in the same setting, and it does not shift much when you skip the action now and then (Wood and Neal, 2007).

Because the link is so steady, breaking a habit has no finish line you can date. Mark Bouton, a psychologist who studies how learning works, reviewed the lab research on changing learned behavior and found that the methods tend to hold the old response back rather than erase it (Bouton, 2014). The old link is still there, only quieter.

A 2021 paper by Gardner and colleagues puts it plainly. People can stop the habitual behavior while the habit itself remains, ready to come back when willpower dips or they return to a familiar place (Gardner and colleagues, 2021).

So “broken” is better read as “the old cue no longer wins.” You can see that in how your weeks are spent long before anyone could say the link is gone.

Two numbers get repeated for breaking habits, and neither was measured for it. The 21 days come from Psycho-Cybernetics, a 1960 self-help book by Maxwell Maltz, a plastic surgeon. He wrote that a mental image needs “a minimum of about 21 days” to change, after watching surgery patients get used to new faces (Maltz, 1960).

The 66 days are real research, but about something else. In that study, 96 volunteers each added one new daily eating, drinking or exercise behavior, and rated how automatic it felt (Lally and colleagues, 2010). Nobody was stopping anything.

Several popular pages on this question say it takes 66 days on average to break a habit. That takes a finding about forming a habit and applies it to the opposite problem. What the 66 days can tell you is how long the replacement might take to become automatic. See how long it takes to form a habit.

The studies point the same way: change what triggers the habit, and give the trigger something else to do. Here is what each line of research found.

Change the setting

Wendy Wood and colleagues followed students who transferred to a new university, to see which habits made the move. Their exercise, newspaper and TV habits survived only where the setting stayed similar, such as reading the paper with others (Wood, Tam and Guerrero Witt, 2005). When the cues changed, the habits broke up.

A move can help on purpose, too. In a real-world study of 800 people, an effort to nudge people toward greener everyday habits worked better for those who had recently moved house. The authors put the window of opportunity at about three months after the move (Verplanken and Roy, 2016). Big life changes like these open a short gap in old habits (Verplanken and Wood, 2006).

Make the action awkward

In a study by Neal and colleagues, people with a strong habit of eating popcorn at the movies ate as much stale popcorn as fresh, so the habit, not the taste, was doing the eating. The habit stopped driving them outside the movie theater, or when they ate with their other hand (Neal and colleagues, 2011). Small changes to how the action is done can break the automatic run.

Watch for the slip

In two studies where people kept diaries of their attempts to control everyday habits, the strategy that controlled strong bad habits was vigilant monitoring: thinking “don’t do it” and watching for slip-ups. No other strategy they recorded helped with strong habits (Quinn and colleagues, 2010). It works by holding the response back, not by weakening the habit.

Replace, do not just remove

A paper written for family doctors by Gardner, Lally and Wardle notes that “it is not possible to form a habit for not doing something” (Gardner, Lally and Wardle, 2012). Putting a new action on the old cue gives the cue something else to start. The 2021 paper calls for exactly this: new habits that override the old ones (Gardner and colleagues, 2021).

Expect a lapse

Old behavior tends to come back in the setting where it was learned, after time away, or under stress. Bouton’s review, from earlier on this page, says frequent lapses should be expected (Bouton, 2014). One bad evening is a data point, not the end.

James Clear’s Atomic Habits, a popular book from 2018, describes a habit as four steps: a cue, a craving, a response and a reward. He gives a law for building each one, and to break a habit he turns each law around: make it invisible, make it unattractive, make it difficult, make it unsatisfying (Clear, 2018).

The law names are his. Below is what each one means in plain words, what the research says about it, and where it shows up in the evenings of the example person further down this page. For the whole loop and how a habit forms in the first place, see habit formation and the habit loop.

Make it invisible: the cue

Take away, hide or change whatever sets the habit off. Of the four steps, this one has the most research behind it, since habits run on cues: the students who changed universities kept their old habits only where the new setting looked like the old one (Wood, Tam and Guerrero Witt, 2005).

The example person tried this on their second Monday. They read on the couch with the phone in the other room, and the phone got 2h that evening, against 2h 30m the Monday before.

Make it unattractive: the craving

Remind yourself what the habit costs, so the want loses some of its pull. Research gives this step the least support once a habit is strong: the habitual popcorn eaters ate stale popcorn as readily as fresh (Neal and colleagues, 2011). What has more support is giving the want somewhere else to go, since you cannot form a habit of not doing something (Gardner, Lally and Wardle, 2012).

The example person did not try to make the phone unappealing. On their second Sunday they bought a novel and wrote that the book comes first now, which gave the after-dinner want a new answer: 20m of reading, then 2h on the phone.

Make it difficult: the response

Put a step between you and the habit. Small amounts of effort count. At a cafeteria salad bar, moving a food about 10 inches farther away, or serving it with tongs instead of a spoon, cut how much people took by 8 to 16% (Rozin and colleagues, 2011). And the popcorn habit stopped running on autopilot when people had to eat with their other hand (Neal and colleagues, 2011).

A phone in another room is that kind of step. On the Monday above it had to be fetched, and it came out only after 20m of reading.

Make it unsatisfying: the reward

Make the habit cost you something you notice soon after. The closest tested idea is the vigilant monitoring from earlier on this page, watching for the slip and telling yourself “don’t do it” (Quinn and colleagues, 2010).

Writing the evening down does a version of this, because the slip lands on the page. The example person’s lapse in week three shows as one evening with 2h on the phone and no reading, inside a week whose phone time still fell, from 14h 45m to 10h 30m.

The research on breaking habits is honest about its limits, so it helps to separate what is settled from what is still open.

• Known: habits run on cues, and changing the cue or the setting disrupts them (Wood, Tam and Guerrero Witt, 2005).
• Known: the old link is held back rather than erased, so lapses are normal (Bouton, 2014).
• Known: a replacement on the same cue can become a habit, on roughly the timeline of any new habit (Lally and colleagues, 2010).
• Not known: a number of days after which an old habit is gone. No study has timed that the way forming has been timed.
• Not known: how much the answer changes between habits. Phone checking, snacking and nail biting have not been compared on one clock.

One more finding shows why the cue matters so much. In two studies where students kept hourly diaries, between a third and a half of what they did was done almost daily in the same place (Wood, Quinn and Kashy, 2002). That is a lot of behavior running on cues, which is why the cue is where to start.

Nobody can promise you a day when the habit is gone. Change the cue, put something better on it, expect a lapse, and watch the weekly hours.

Tonight, move the thing that starts it. Then count what the evening gives back.

1. Lally, P., van Jaarsveld, C. H. M., Potts, H. W. W. and Wardle, J. (2010). How are habits formed: Modelling habit formation in the real world. European Journal of Social Psychology, 40(6), 998 to 1009.
2. Maltz, M. (1960). Psycho-Cybernetics. Prentice-Hall; quoted from the publisher's preview of the current Profile Books edition.
3. Wood, W. and Neal, D. T. (2007). A new look at habits and the habit-goal interface. Psychological Review, 114(4), 843 to 863.
4. Bouton, M. E. (2014). Why behavior change is difficult to sustain. Preventive Medicine, 68, 29 to 36.
5. Gardner, B., Richards, R., Lally, P., Rebar, A., Thwaite, T. and Beeken, R. J. (2021). Breaking habits or breaking habitual behaviours? Old habits as a neglected factor in weight loss maintenance. Appetite, 162, 105183.
6. Wood, W., Tam, L. and Guerrero Witt, M. (2005). Changing circumstances, disrupting habits. Journal of Personality and Social Psychology, 88(6), 918 to 933.
7. Verplanken, B. and Roy, D. (2016). Empowering interventions to promote sustainable lifestyles: Testing the habit discontinuity hypothesis in a field experiment. Journal of Environmental Psychology, 45, 127 to 134.
8. Verplanken, B. and Wood, W. (2006). Interventions to break and create consumer habits. Journal of Public Policy and Marketing, 25(1), 90 to 103.
9. Neal, D. T., Wood, W., Wu, M. and Kurlander, D. (2011). The pull of the past: When do habits persist despite conflict with motives? Personality and Social Psychology Bulletin, 37(11), 1428 to 1437.
10. Quinn, J. M., Pascoe, A., Wood, W. and Neal, D. T. (2010). Can't control yourself? Monitor those bad habits. Personality and Social Psychology Bulletin, 36(4), 499 to 511.
11. Gardner, B., Lally, P. and Wardle, J. (2012). Making health habitual: the psychology of 'habit-formation' and general practice. British Journal of General Practice, 62(605), 664 to 666.
12. Wood, W., Quinn, J. M. and Kashy, D. A. (2002). Habits in everyday life: Thought, emotion, and action. Journal of Personality and Social Psychology, 83(6), 1281 to 1297.
13. Clear, J. (2018). Atomic Habits: An Easy and Proven Way to Build Good Habits and Break Bad Ones (the author's summary of its framework). Avery; the four laws as the author lists them on jamesclear.com.
14. Rozin, P., Scott, S., Dingley, M., Urbanek, J. K., Jiang, H. and Kaltenbach, M. (2011). Nudge to nobesity I: Minor changes in accessibility decrease food intake. Judgment and Decision Making, 6(4), 323 to 332.