I usually just add a little of this and a squirt of that when making whipped cream, but I measured things out today so I could tell you (approximately!) how I make it.
Low Carb Whipped Cream
Put all ingredients in a medium bowl and whip with a mixer or egg beaters until desired thickness. I usually like it stiff enough to hold soft peaks.
This contains about 2 net carbs. How many servings it makes depends on how much you want to add to a serving. I eat the entire amount in one serving when having a double-decker Low Carb Shortpuffs dessert, but it can serve several people if used mostly for garnish.