I think they vary actually. One brand I buy from my local grocery store has .6 per 2 Tbls....making it 4.8 carbs per cup. Another brand I buy at Walmart says 1g per 2 Tbls making that 8 carbs per cup. I never know either, so I just go by the .6 per 2 Tbls. most of the time. I guess the best way is just go by the label on what you buy....if it says 0 carbs, use the .6 per serving.
Vicky