Is my Anchor Hocking Oven Basics glass measuring cup inaccurate? For measuring I usually use my red plastic Betty Crocker cups.
While rearranging some dishes, I noticed the 1 cup line on the 2 cup Anchor H one looked off - greater than one cup. I poured one cup from the plastic one into the 2cup Anchor Hocking one and there was a discrepancy. See photo. Also true of the glass 1 cup AH one.
This seems enough to make a difference in some recipes and general measuring. I appreciate any thoughts.
I'd get a third measuring tool to see which one is wrong.

One way to test this is to measure by weight (and IMO, all recipes should list ingredients by weight instead of volume)

1 cup of water is about 236ml which is 236g.

Get 1 cup from your red cup and weight it.
Get 1 cup from your glass cup and weight it.

It should tell you which one is right.

And to answer your question, yes, for some recipes, if you add too much or too liltle liquid it will not result in different results (either too dry or too wet).