Does It Really Take 21 Days to Form a Habit? Here’s What Science Says

You’ve probably heard the popular saying, “It takes 21 days to form a habit.” Whether you’re trying to exercise regularly, eat healthier, or learn a new skill, this idea is often tossed around as the magic number for behavioral change. But is it true? Let’s dive into the science to uncover if it really takes 21 days to form a habit—and what might actually help you stick to your goals.

The Origins of the 21-Day Habit Myth

The 21-day rule for habit formation traces back to Dr. Maxwell Maltz, a plastic surgeon in the 1960s who observed that his patients took about 21 days to adjust to changes in their appearance after surgery. In his popular book Psycho-Cybernetics, he mentioned that it took about three weeks for people to adopt a new mindset or behavior.

While Maltz’s observation made sense for his patients, over time, people generalized this number to mean that it takes exactly 21 days to form any habit. It became a widely accepted "fact" in self-help circles, but there’s more to habit formation than this simple timeframe.

What Science Really Says About Habit Formation

According to research published in the European Journal of Social Psychology, the idea that 21 days is enough to form a habit isn’t exactly accurate. In a 2009 study by Phillippa Lally and her team, it was found that on average, it actually takes 66 days for a new behavior to become automatic. However, the exact time can vary greatly depending on the person and the complexity of the habit. Some habits took as little as 18 days to form, while others took up to 254 days.

This research shows that habit formation is not a one-size-fits-all process. It depends on a variety of factors, including the individual’s motivation, consistency, and the type of habit they’re trying to build.

Why It Might Take Longer (or Shorter) for You

While 21 days may not be enough for everyone, you might be able to form a habit more quickly if:

1. The habit is simple: Small, straightforward actions like drinking a glass of water every morning or stretching for five minutes can be easier to adopt and may take less time.

2. You have strong motivation: If the habit aligns with your values and goals, you’re more likely to stick with it, making it easier to establish the behavior.

3. You use a habit loop: Charles Duhigg’s The Power of Habit highlights the importance of a “cue, routine, reward” loop in habit formation. When you consistently follow this pattern, the habit becomes more ingrained.

On the flip side, forming complex or less enjoyable habits (like going to the gym regularly or changing your diet) may require more time, support, and effort to truly stick.

How to Speed Up the Habit-Forming Process

If you want to build a habit faster, here are a few science-backed strategies that can help:

• Start small: Focus on one simple habit at a time. Trying to overhaul your entire life at once can lead to burnout.

• Be consistent: Doing your habit daily can help it stick. Even if you can’t commit to an hour at the gym, doing a five-minute workout every day builds the routine.

• Track your progress: Keeping a habit tracker or journal can reinforce positive behavior and keep you motivated as you watch your streak grow.

• Find accountability: Share your goal with a friend or join a community. Knowing someone is checking in on your progress increases the likelihood that you’ll stay committed.

The Bottom Line: Does It Take 21 Days to Form a Habit?

The 21-day rule may be catchy, but science suggests it’s overly simplistic. While it’s possible to start seeing progress in three weeks, true habit formation often takes much longer—sometimes two months or more. The key to success is consistency, motivation, and a clear plan to build the habit step by step.

So, the next time you set out to form a new habit, don’t get discouraged if you’re still struggling after 21 days. Stick with it, and remember that sustainable change is more important than arbitrary timelines.