Ive asked this question before.
The easiest way is count the total carbs on anything you eat which is the same as net carbs.
Its something to do with the rest of the world dont take out fiber so you have to minus the fiber from the total carbs to give net carbs, but as we are in the uk, we dont have to do this.
Just count the total carbs from any packs as net carbs.
Hope this makes sense!