How many ounces are in a normal sized bag of chocolate chips?

The best way to know for sure is to invest in a digital scale (food or postage-type)and weigh all your food.

I tested the previous answer for myself with Lay's brand Potato Chips (just plain, no ruffles) and found that there were, in fact, 24 chips (whole, each approx. the same size) in an ounce.

Dorito's Nacho Cheese were 10 chips/1 oz.

Tostito's Restaurant Style Corn Chips were 6 chips/1 oz.

Note: manufacturers will also round up to the nearest ounce on labeling (i.e. 0.6 oz becomes 1.0 oz.)