Well there are different stages of Atkins, but on the first one (Induction) it isn't the percentage of carbs you eat, but the number of grams. You're supposed to stick to under 20 grams of carbs a day, and even then you should be getting them from leafy greens, not sugar, flour, fruit, etc. To get the details on the rules check out
www.AtkinsCenter.com and read up on Induction