Sorry if this has been asked before, but I couldn't find it in a search.

I'm in Canada, and we have Splenda in the big boxes. According to Atkins, one should count one carb per packet of Splenda used, but how does that translate to the powdered Splenda? It's a straight substitution for sugar, according tot he box - if you use 1 cup of sugar, use 1 cup of Splenda. But what should the carb count be, say per cup or per tbsp or tsp? It doesn't say on the box.