I can't believe I just did this, but after buying a bag of Ruffles Light, Fat Free chips and getting ready to count out 'my fifteen' and finding them all broken- a lightbulb came on.
I put a handful of chips onto a paper towel, walked to the postage machine and promptly laid it out onto it. 1.5oz of chips! Voila! Just perfect.
Thank god no one saw me doing that hahaha.
Still, it works, and really keeps you from underguessing chip points.