As Brunneria said the best option is to try and test. I can manage a small pack (24g pack about 15g carbs), either as part of a meal or as a morning snack (I have quite a long time between breakfast and lunch on a work day). It is also a case of remembering to count the carbs as part of my daily or meal allowance.
Keep away from the 'healthy' varieties, such as the light or baked crisps they have a far higher carb content than standard ones. I also find I am best not to buy large packs with the intention of eating them over several days, it never works like that, a multipack of small packets works best and they tend to be smaller packs than the individual packs you can get in a newsagents etc.