How long does it take to form a habit?

We all have habits – some good, some bad, and some we desperately wish we could stick to. But exactly how long does it take to develop a habit? How much time do you need to dedicate to something so it becomes a lasting part of your routine? 

You might have heard that it takes '21 days to form a habit' and that your behaviour sticks after three weeks of effort and dedication. We hate to break it to you, but science says otherwise.¹ 

Here, we’ll uncover the real timeline it takes to form a new habit and some top tips to help you on your way. 

What is a habit?

A habit is a behaviour you do without much thought, almost as if running on autopilot.¹ Think brushing your teeth, making coffee in the morning or scrolling social media. You don’t wake up and think, should I brush my teeth today? You just do it. That’s the power of habits: they make life easier by automating small daily actions.

But don’t be fooled by their simplicity. These small habits quickly add up and can positively impact your healthy behaviours, productivity and long-term goals.¹,² Understanding how to make positive habits (and break negative ones) is crucial for building a lifestyle that supports your wellbeing.¹ 

How long does it take to establish a habit?

Habits are great for starting healthy lifestyle changes and guiding you towards your long-term goals.¹,² But how long does it take to create a habit? 

Forget the ‘21-day rule’ – it’s a total myth. This three-week theory comes from the 1960 book Psycho-Cybernetics, where plastic surgeon Maxwell Maltz noted that it took his patients 21 days to adjust to their new appearance.³ That timeline got misinterpreted and applied to habits, but the reality is a little more complicated. 

Depending on what habit you’re trying to build, the time frame can vary. A 2024 meta-analysis looking specifically at health-related habits backed this up: on average, you’re looking at 2 to 5 months to create a new, healthy habit – not 21 days.¹ This can vary depending on the individual and in different situations.¹

What influences how long it takes to create a habit?

Some habits stick more easily, while others feel impossible to maintain. That’s because the timeline for habit formation depends on a few key factors.

1. The simplicity of the habit

Simple actions, like drinking a glass of water every morning or flossing your teeth every day, are easier to turn into habits.¹ This could be because they come with instant gratification – you feel refreshed after drinking water or get that just-left-the-dentist clean feeling from flossing.¹

More complex behaviours, like exercising regularly and eating a healthier diet, are more difficult to form into habits.¹

2. Consistency and repetition

The golden rule for forming habits? Repetition. This is well-documented in psychological research: in the most basic sense, for a behaviour to become a habit, you need to do it again and again – and again.¹

The good news? Being kind to yourself about any setbacks can actually help with a positive mindset which, in turn, can help you make longer-term changes.⁴

So, if you skip a gym session or don’t drink enough water one day, don’t stress. Mistakes happen, and it’s important to forgive yourself so that you can keep moving forward. 

3. Environment and triggers

Although you might like to think you’re in control of all your actions, many behaviours are impacted by your environment.⁵ For instance, living near a green space may make you more likely to exercise,⁶ while air pollution and crime rates can influence how well you sleep.⁷ 

Luckily, you don’t have to move to a park-filled utopia to build better habits. Studies show that simple tweaks, such as putting your gym bag by the door, make you more likely to follow through with exercise.⁸ 

The same is true for negative habits you want to break. If there’s a cookie on the side, you’re potentially more likely to eat it. Setting up your environment for success can make it easier for you to stay on track, making habits form more quickly.¹ 

The science of habit formation

By now, you know forming a healthy habit takes 2 to 5 months on average.¹ But you also know there’s variation in this timeframe, depending on the simplicity of the habit, how often you repeat it, and your environment.¹ In other words, establishing habits is complex. 

To explain some of the mystery, it helps to look at the neuroscience. Habit formation happens in the brain.⁹ When you repeat a behaviour, your brain strengthens the neural pathways associated with that action.⁹ Over time, these pathways become stronger and form a ‘habit loop’, making the behaviour feel automatic.⁹

The more a behaviour is repeated, the more it shifts from being a conscious, outcome-driven action to an automatic response.¹ Habits that you enjoy or are instantly rewarding are easier to stick to.¹  The brain quickly notices patterns between actions and rewards (that give our brains a dopamine hit), so the better something makes you feel, the more likely it will become a habit.⁹

Through these reward pathways firing repeatedly, your brain literally rewires itself, shifting control from your goal-oriented brain regions to the habit-forming structures that keep things running smoothly in the background.⁹

How to form a habit that sticks

Want to make a habit second nature? Here’s how to outsmart your brain and make healthy behaviours feel automatic:

• Start small. The harder the habit, the tougher it is to stick with.¹ If you don’t work out at all, don’t vow to hit the gym for an hour every day; start with a 5-minute walk. Tiny wins build momentum, and before you know it, that short walk turns into a full workout routine.
• Reward yourself. Your brain loves rewards and quickly picks up on patterns linking actions to feel-good sensations.⁹ Whether it’s a celebratory coffee after a morning run or ticking off a habit tracker, giving yourself a little dopamine boost may reinforce the habit.
• Try habit stacking. Want to start meditating? Pair it with brushing your teeth. Want to drink more water? Have a glass with your morning coffee. Stacking habits may make them easier to remember and harder to skip.⁸
• Be patient; your brain is rewiring. Habits don’t happen overnight, and it’s important to forgive yourself if something hasn't gone to plan.⁴ Instead of an ‘all or nothing’ mindset, think of it as a long-term game. Keep going – you’ve got this.
• Take advantage of technology. Your brain has enough to remember, so why not get a little help? The H&B&Me app keeps you on track with reminders, habit insights and motivation boosts, so sticking to your new health and wellness goals is easier than ever. 

How H&B&Me can help you form better habits

How many days does it take to form a habit? While there’s no definitive answer, establishing new habits is easier and quicker with the right support to help you feel more motivated and become more consistent. The H&B&Me app does precisely that, helping you: 

Track your habits and progress easily and effortlessly:

• Set personalised habit goals and join expert-created challenges
• Get science-backed insights tailored to your journey
• Stay accountable with reminders and motivation boosts

So, are you ready to start working towards making new habits that stick? Download the H&B&Me app and start making small daily changes today that may lead to healthier habits.

References

1. Singh B, Murphy A, Maher C, Smith AE. Time to Form a Habit: A Systematic Review and Meta-Analysis of Health Behaviour Habit Formation and Its Determinants. Healthcare [Internet]. 2024 Dec 9;12(23):2488. Available from: https://www.mdpi.com/2227-9032/12/23/2488#B5-healthcare-12-02488 

2. Stojanovic M, Wood W. Beyond Deliberate Self-Control: Habits Automatically Achieve Long-Term Goals. Current Opinion in Psychology. 2024 Sep 1;101880–0. Available from: https://www.sciencedirect.com/science/article/abs/pii/S2352250X24000939?via%3Dihub 

3. New Psycho-Cybernetics [Internet]. Google Books. 2025 [cited 2025 Feb 20]. Available from: https://books.google.co.uk/books?hl=en&lr=&id=IJcXAwAAQBAJ&oi=fnd&pg=PA1&ots=ImKDmnEAoM&sig=IYWnTp_ESzifdgOCP0p3oLCFIMs&redir_esc=y#v=onepage&q&f=false 

4. Biber DD, Ellis R. The effect of self-compassion on the self-regulation of health behaviors: A systematic review. Journal of Health Psychology. 2017 Jun 15;24(14):2060–71.

‌5. Albarracín D, Dai W. Chapter Three - The impact of the environment on behavior [Internet]. Gawronski B, editor. Vol. 69, ScienceDirect. Academic Press; 2024. p. 151–201. Available from: https://www.sciencedirect.com/science/article/abs/pii/S0065260123000308 

‌6. Song Y, Li H, Yu H. Effects of green space on physical activity and body weight status among Chinese adults: a systematic review. Frontiers in Public Health. 2023 Jul 20;11. Available from: https://pubmed.ncbi.nlm.nih.gov/37546310/ 

7. Billings ME, Hale L, Johnson DA. Physical and Social Environment Relationship With Sleep Health and Disorders. Chest. 2020 May;157(5):1304–12. Available from:  https://pmc.ncbi.nlm.nih.gov/articles/PMC7268445/

8. Gardner B, Arden MA, Brown D, Eves FF, Green J, Hamilton K, et al. Developing habit-based Health Behaviour Change interventions: Twenty-one questions to Guide Future Research. Psychology & Health [Internet]. 2021 Nov 14;38(4):1–23. Available from: https://www.tandfonline.com/doi/full/10.1080/08870446.2021.2003362 

9. Wyatt Z. The Neuroscience of Habit Formation. Neurology and neuroscience. 2024 Mar 30;5(1). Available from: https://www.researchgate.net/publication/378681505_The_Neuroscience_of_Habit_Formation