Measuring Question

I got into this discussion with someone at work today about measuring and was informed that 8 ounces doesn't make a cup.

I disagree. 

But what do I know...I mean...I only have a glass measuring cup, plastic measuring cups, a SCALE...

Sorry...outburst.

So I guess after six months of measuring and scooping my question would be...when is a cup not a cup?

United States "legal" cup

The cup currently used in the United States for nutrition labeling is defined in United States law as 240 mL.^[1][2][3]

1 U.S. "legal" cup	=	240	millilitres
	=	16	international tablespoons
	=	12	Australian tablespoons
	≈	8.12	U.S. customary fluid ounces
	≈	8.45	imperial fluid ounces

What about weighing solids?

 Depending upon the density of the item, 8 ounces (non-fluid) may not be a cup. 8ish fluid ounces does indeed equal a cup. But 8 ounces in weight could be more or less than a cup depending upon the density of the non-fluid item you are weighing.

Does that make sense?

A cup is a volume measure.  An ounce can either be volume or weight.  Depends on which you are talking about.  We were told to use volume because our pouch doesn't have a scale, it has a volume.  I do use a scale now that I am eating stuff that doesn't fit in a cup well so I know how much weight of meats to count.

Sometimes it does, sometimes it doesn't.  8 ounces of water is roughly a cup.  8 ounces of my Special K Cereal is roughly 7 cups.  When you are talking liquids the voume to weight is pretty dead on, but with solids anything goes.  A cup of steak is not going to weigh 8 ounces.