That is really a personal matter.

It varies from one person to another.

In Dr Atkin's book he talks about OWL and Maintenance. You should increase your carb intake by 5 grams of carbs per day one week at a time. I actually recommend 2 weeks between each increase due to that scale up/down effect we get into from water retention.

It will look something like this:

Week 1-2 20 carbs a day = induction
Week 3-4 25 carbs a day
Week 5-6 30 carbs a day
Week 7-8 35 carbs a day
Week 9-10 40 carbs a day
and so on

The point is to get to a carb value that actually makes you START gaining weight. That is your max number. You are then to back off of that number until you hit goal. Then for the rest of your life as long as you stay below that carb max number you should be able to maintain that perfect weight.

Now if you increase your exercise routine you will have to redo this because of the increase in your metobolism.

As you can see it really varies from person to person since no two people have the same metobolism.