How long does it take to make a habit? How long does it take to make a routine?

I have been thinking about habits versus routines, and how long a good estimate when it comes to a habit versus a routine.  Specifically, I have started going to the gym again regularly, and have tried to determine what stage I am in in regards to a habit or a routine.

I think a habit is when something is completed 5 consecutive days.  Therefore the gym is now a habit for me, because I’ve gone 5 times.  A habit is the beginning of a routine, and is indicative that you are going to continue your habit until it becomes a routine.

I believe a routine to be when something occurs for 4 consecutive weeks.  There is a long way to go between a habit and a routine.  Once you hit the 4 week mark, you absolutely are going to stick to that behavior for a long time. 

People tend to fall out of habits because it becomes too repetitive, and many of our goals don’t have short term rewards.  Just like going to the gym, the payoffs happen over the long run, and people lose focus that you aren’t going to drop 20 lbs a week. 

Do you have different visions for what makes a habit and what makes a routine?  Write it in the comments to start a discussion!