How long does it take to form a habit?
There's no single number: in the best-known study, a daily habit took a median of about 66 days to feel automatic, and the estimates for different people and habits ranged from 18 to 254 days. The popular "21 days" figure doesn't come from it.
What the study did
Researchers followed 96 volunteers for 12 weeks. Each repeated one eating, drinking or activity habit every day in the same situation, and rated how automatic it felt. Automaticity rose quickly at first, then leveled off, at very different speeds for different people and habits (Lally et al. 2010). The longest times are estimates projected from that curve, since the study itself lasted 12 weeks.
An occasional skipped day didn't undo it
Missing a day now and then did not seriously set people back; their progress toward automaticity soon picked up again. It is one study, so treat 66 days as a rough guide, not a deadline.
What helps it along
Tie the habit to a specific cue, and plan for the obstacle: "When I finish my morning coffee, I'll do ten minutes of mobility," and "If I'm short on time, I'll do two." Plans like these measurably improve follow-through, and they work best as a pair (Gollwitzer; Sniehotta).
In Rewarding Habits
What the app does
Each habit's ocean on your phone grows with your completions, at your own pace, and time away never dims it. You can add an if-then coping plan to a habit, and stack it onto a routine you already have.
Sources
- Lally, P. et al. (2010). How are habits formed: Modelling habit formation in the real world. European Journal of Social Psychology. A median of ~66 days.
- Gollwitzer, P.; Sniehotta, F. et al. Implementation and coping planning (94 tests, d 0.65).
Rewarding Habits is a skill-building app informed by psychological science. It isn't therapy or a crisis service. Every source above is also on our science page, with more of the research behind the app.