Carb values can vary greatly depending on the brand, the levels of ingredients used by each manufacturer. If the bottle says 0 carbs, it is likely to be less than one gram. Company does not have to declare the amount if it is less than one gram.

The carb counter I use says 2.5 per 100 gram average for all brands.

Fitday actually says 1.26 grams per tablespoon or 20 grams per cup. I think that sounds about right

Hope that helps.
Kim